diff --git a/eng/common-tests/ChangeLog-Operations.Tests.ps1 b/eng/common-tests/ChangeLog-Operations.Tests.ps1
index 2a406e80aff..6c76d9bd29c 100644
--- a/eng/common-tests/ChangeLog-Operations.Tests.ps1
+++ b/eng/common-tests/ChangeLog-Operations.Tests.ps1
@@ -225,3 +225,299 @@ Describe "Integration: Update Changelog Entry and Write Back" {
         $updatedEntries["0.9.0"] | Should -Not -BeNullOrEmpty
     }
 }
+
+Describe "Python post-release changelog parsing" {
+    BeforeEach {
+        $global:Language = "python"
+    }
+
+    AfterEach {
+        $global:Language = ""
+    }
+
+    It "Should parse changelog with GA post-release version '1.0.0.post1'" {
+        $changelogContent = @"
+# Release History
+
+## 1.0.0.post1 (2025-03-01)
+
+### Other Changes
+
+- Updated package metadata for distribution
+
+## 1.0.0 (2025-02-15)
+
+### Features Added
+
+- Initial GA release
+"@
+        $entries = Get-ChangeLogEntriesFromContent $changelogContent
+        $entries | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post1"].ReleaseVersion | Should -Be "1.0.0.post1"
+        $entries["1.0.0.post1"].ReleaseStatus | Should -Be "(2025-03-01)"
+        $entries["1.0.0.post1"].Sections.ContainsKey("Other Changes") | Should -BeTrue
+        $entries["1.0.0"] | Should -Not -BeNullOrEmpty
+    }
+
+    It "Should parse changelog with beta post-release version '1.0.0b2.post1'" {
+        $changelogContent = @"
+# Release History
+
+## 1.0.0b2.post1 (2025-03-01)
+
+### Other Changes
+
+- Updated classifier metadata for beta release
+
+## 1.0.0b2 (2025-02-15)
+
+### Features Added
+
+- Beta feature
+"@
+        $entries = Get-ChangeLogEntriesFromContent $changelogContent
+        $entries | Should -Not -BeNullOrEmpty
+        $entries["1.0.0b2.post1"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0b2.post1"].ReleaseVersion | Should -Be "1.0.0b2.post1"
+        $entries["1.0.0b2.post1"].Sections.ContainsKey("Other Changes") | Should -BeTrue
+        $entries["1.0.0b2"] | Should -Not -BeNullOrEmpty
+    }
+
+    It "Should parse changelog with alpha post-release version '2.0.0a20201208001.post2'" {
+        $changelogContent = @"
+# Release History
+
+## 2.0.0a20201208001.post2 (2025-03-01)
+
+### Other Changes
+
+- Updated alpha package metadata
+
+## 2.0.0a20201208001 (2025-02-15)
+
+### Features Added
+
+- Alpha feature
+"@
+        $entries = Get-ChangeLogEntriesFromContent $changelogContent
+        $entries | Should -Not -BeNullOrEmpty
+        $entries["2.0.0a20201208001.post2"] | Should -Not -BeNullOrEmpty
+        $entries["2.0.0a20201208001.post2"].ReleaseVersion | Should -Be "2.0.0a20201208001.post2"
+        $entries["2.0.0a20201208001"] | Should -Not -BeNullOrEmpty
+    }
+
+    It "Should parse changelog with unreleased post-release version" {
+        $changelogContent = @"
+# Release History
+
+## 1.0.0.post2 (Unreleased)
+
+### Other Changes
+
+## 1.0.0.post1 (2025-02-15)
+
+### Other Changes
+
+- Updated package metadata
+"@
+        $entries = Get-ChangeLogEntriesFromContent $changelogContent
+        $entries | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post2"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post2"].ReleaseStatus | Should -Be "(Unreleased)"
+        $entries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+    }
+
+    It "Should parse changelog with multiple post-release versions" {
+        $changelogContent = @"
+# Release History
+
+## 1.0.0.post3 (2025-04-01)
+
+### Other Changes
+
+- Updated package classifiers
+
+## 1.0.0.post2 (2025-03-15)
+
+### Other Changes
+
+- Updated package description
+
+## 1.0.0.post1 (2025-03-01)
+
+### Other Changes
+
+- Updated package metadata
+
+## 1.0.0 (2025-02-15)
+
+### Features Added
+
+- Initial release
+"@
+        $entries = Get-ChangeLogEntriesFromContent $changelogContent
+        $entries | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post3"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post2"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0"] | Should -Not -BeNullOrEmpty
+    }
+}
+
+Describe "Python post-release changelog sorting" {
+    BeforeEach {
+        $global:Language = "python"
+    }
+
+    AfterEach {
+        $global:Language = ""
+    }
+
+    It "Should sort post-release versions after their base version" {
+        $changelogContent = @"
+# Release History
+
+## 1.0.0 (2025-02-15)
+
+### Features Added
+
+- Initial release
+
+## 1.0.0.post1 (2025-03-01)
+
+### Other Changes
+
+- Updated package metadata
+"@
+        $entries = Get-ChangeLogEntriesFromContent $changelogContent
+        $sorted = Sort-ChangeLogEntries -changeLogEntries $entries
+
+        # post1 should come before (sort higher than) base 1.0.0 in descending sort
+        $sortedVersions = @($sorted | ForEach-Object { $_.ReleaseVersion })
+        $postIndex = [array]::IndexOf($sortedVersions, "1.0.0.post1")
+        $baseIndex = [array]::IndexOf($sortedVersions, "1.0.0")
+        $postIndex | Should -BeLessThan $baseIndex
+    }
+}
+
+Describe "Python post-release changelog integration" {
+    BeforeEach {
+        $global:Language = "python"
+        $script:tempChangelogPath = Join-Path ([System.IO.Path]::GetTempPath()) "CHANGELOG_$([System.Guid]::NewGuid().ToString()).md"
+    }
+
+    AfterEach {
+        $global:Language = ""
+        if (Test-Path $script:tempChangelogPath) {
+            Remove-Item -Path $script:tempChangelogPath -Force -ErrorAction SilentlyContinue
+        }
+    }
+
+    It "Should round-trip a changelog with post-release versions" {
+        $initialChangelog = @"
+# Release History
+
+## 1.0.0.post1 (2025-03-01)
+
+### Other Changes
+
+- Updated package metadata
+
+## 1.0.0 (2025-02-15)
+
+### Features Added
+
+- Initial release
+"@
+        Set-Content -Path $script:tempChangelogPath -Value $initialChangelog
+
+        $entries = Get-ChangeLogEntries -ChangeLogLocation $script:tempChangelogPath
+        $entries | Should -Not -BeNullOrEmpty
+        $entries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+        $entries["1.0.0"] | Should -Not -BeNullOrEmpty
+
+        # Write back and re-read
+        Set-ChangeLogContent -ChangeLogLocation $script:tempChangelogPath -ChangeLogEntries $entries
+
+        $reReadEntries = Get-ChangeLogEntries -ChangeLogLocation $script:tempChangelogPath
+        $reReadEntries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+        $reReadEntries["1.0.0.post1"].ReleaseVersion | Should -Be "1.0.0.post1"
+        $reReadEntries["1.0.0.post1"].ReleaseStatus | Should -Be "(2025-03-01)"
+        $reReadEntries["1.0.0"] | Should -Not -BeNullOrEmpty
+    }
+
+    It "Should update a post-release changelog entry content" {
+        $initialChangelog = @"
+# Release History
+
+## 1.0.0.post1 (Unreleased)
+
+### Other Changes
+
+## 1.0.0 (2025-02-15)
+
+### Features Added
+
+- Initial release
+"@
+        Set-Content -Path $script:tempChangelogPath -Value $initialChangelog
+
+        $entries = Get-ChangeLogEntries -ChangeLogLocation $script:tempChangelogPath
+        $postEntry = $entries["1.0.0.post1"]
+        $postEntry | Should -Not -BeNullOrEmpty
+
+        $newContent = "### Other Changes`n`n- Updated package metadata`n- Updated readme formatting"
+        Set-ChangeLogEntryContent -ChangeLogEntry $postEntry -NewContent $newContent -InitialAtxHeader $entries.InitialAtxHeader
+        Set-ChangeLogContent -ChangeLogLocation $script:tempChangelogPath -ChangeLogEntries $entries
+
+        $updatedEntries = Get-ChangeLogEntries -ChangeLogLocation $script:tempChangelogPath
+        $updatedEntries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+        $updatedEntries["1.0.0.post1"].Sections.ContainsKey("Other Changes") | Should -BeTrue
+
+        $updatedContent = Get-Content -Path $script:tempChangelogPath -Raw
+        $updatedContent | Should -Match "Updated package metadata"
+        $updatedContent | Should -Match "Updated readme formatting"
+
+        # Verify the base version is preserved
+        $updatedEntries["1.0.0"] | Should -Not -BeNullOrEmpty
+    }
+
+    It "Should preserve post-release entries when adding a new version" {
+        $initialChangelog = @"
+# Release History
+
+## 1.0.0.post1 (2025-03-01)
+
+### Other Changes
+
+- Updated package metadata
+
+## 1.0.0 (2025-02-15)
+
+### Features Added
+
+- Initial release
+"@
+        Set-Content -Path $script:tempChangelogPath -Value $initialChangelog
+
+        $entries = Get-ChangeLogEntries -ChangeLogLocation $script:tempChangelogPath
+
+        # Add a new version entry
+        $newEntry = [pscustomobject]@{
+            ReleaseVersion = "1.1.0"
+            ReleaseStatus  = "(Unreleased)"
+            ReleaseTitle   = "## 1.1.0 (Unreleased)"
+            ReleaseContent = @("", "### Features Added", "", "- New feature for 1.1.0")
+            Sections = @{ "Features Added" = @("", "- New feature for 1.1.0") }
+        }
+        $entries["1.1.0"] = $newEntry
+
+        Set-ChangeLogContent -ChangeLogLocation $script:tempChangelogPath -ChangeLogEntries $entries
+
+        $updatedEntries = Get-ChangeLogEntries -ChangeLogLocation $script:tempChangelogPath
+        $updatedEntries["1.1.0"] | Should -Not -BeNullOrEmpty
+        $updatedEntries["1.0.0.post1"] | Should -Not -BeNullOrEmpty
+        $updatedEntries["1.0.0"] | Should -Not -BeNullOrEmpty
+    }
+}
diff --git a/eng/common-tests/SemVer.Tests.ps1 b/eng/common-tests/SemVer.Tests.ps1
new file mode 100644
index 00000000000..1044813e105
--- /dev/null
+++ b/eng/common-tests/SemVer.Tests.ps1
@@ -0,0 +1,393 @@
+Import-Module Pester
+
+BeforeAll {
+    . $PSScriptRoot/../common/scripts/SemVer.ps1
+}
+
+Describe "Post-release version parsing - Default convention (negative tests for non-Python languages)" {
+    BeforeEach {
+        $global:Language = ""
+    }
+
+    It "Should parse '1.0.0-post.1' as prerelease label 'post', NOT as post-release" {
+        $ver = [AzureEngSemanticVersion]::ParseVersionString("1.0.0-post.1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.PrereleaseLabel | Should -Be "post"
+        $ver.PrereleaseNumber | Should -Be 1
+        $ver.IsPrerelease | Should -BeTrue
+        $ver.IsPostRelease | Should -BeFalse
+    }
+
+    It "Should fail to parse '2.0.0-beta.1-post.1' (regex doesn't match)" {
+        $ver = [AzureEngSemanticVersion]::ParseVersionString("2.0.0-beta.1-post.1")
+        $ver | Should -BeNullOrEmpty
+    }
+
+    It "Should fail to parse '1.2.3-alpha.20200828.9-post.3' (regex doesn't match)" {
+        $ver = [AzureEngSemanticVersion]::ParseVersionString("1.2.3-alpha.20200828.9-post.3")
+        $ver | Should -BeNullOrEmpty
+    }
+}
+
+Describe "Post-release version parsing - Python convention" {
+    It "Should parse GA post-release '1.0.0.post1'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.Major | Should -Be 1
+        $ver.Minor | Should -Be 0
+        $ver.Patch | Should -Be 0
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.PrereleaseLabel | Should -BeNullOrEmpty
+        $ver.IsPrerelease | Should -BeFalse
+        $ver.VersionType | Should -Be "GA"
+    }
+
+    It "Should parse patch version post-release '1.2.3.post5'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.2.3.post5")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.Major | Should -Be 1
+        $ver.Minor | Should -Be 2
+        $ver.Patch | Should -Be 3
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 5
+        $ver.PrereleaseLabel | Should -BeNullOrEmpty
+        $ver.IsPrerelease | Should -BeFalse
+        $ver.VersionType | Should -Be "Patch"
+    }
+
+    It "Should parse beta prerelease post-release '1.0.0b2.post1'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2.post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.Major | Should -Be 1
+        $ver.Minor | Should -Be 0
+        $ver.Patch | Should -Be 0
+        $ver.PrereleaseLabel | Should -Be "b"
+        $ver.PrereleaseNumber | Should -Be 2
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.IsPrerelease | Should -BeTrue
+        $ver.VersionType | Should -Be "Beta"
+    }
+
+    It "Should parse alpha prerelease post-release '2.0.0a20201208001.post2'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("2.0.0a20201208001.post2")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.Major | Should -Be 2
+        $ver.Minor | Should -Be 0
+        $ver.Patch | Should -Be 0
+        $ver.PrereleaseLabel | Should -Be "a"
+        $ver.PrereleaseNumber | Should -Be 20201208
+        $ver.BuildNumber | Should -Be "001"
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 2
+        $ver.IsPrerelease | Should -BeTrue
+    }
+
+    It "Should parse zero-major post-release '0.1.0.post1'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("0.1.0.post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.Major | Should -Be 0
+        $ver.Minor | Should -Be 1
+        $ver.Patch | Should -Be 0
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.IsPrerelease | Should -BeTrue
+        $ver.VersionType | Should -Be "Beta"
+    }
+
+    It "Should parse implicit post-release number '1.0.0.post' as post0" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.Major | Should -Be 1
+        $ver.Minor | Should -Be 0
+        $ver.Patch | Should -Be 0
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.PrereleaseLabel | Should -BeNullOrEmpty
+        $ver.IsPrerelease | Should -BeFalse
+        $ver.VersionType | Should -Be "GA"
+    }
+
+    It "Should parse implicit prerelease post-release '1.0.0b2.post' as post0" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2.post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsSemVerFormat | Should -BeTrue
+        $ver.PrereleaseLabel | Should -Be "b"
+        $ver.PrereleaseNumber | Should -Be 2
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.IsPrerelease | Should -BeTrue
+    }
+}
+
+Describe "Post-release version ToString round-trip - Default convention (non-Python languages don't support post-release, so should round-trip as prerelease)" {
+    BeforeEach {
+        $global:Language = ""
+    }
+
+    It "'1.0.0-post.1' round-trips as prerelease (label 'post'), not post-release" {
+        $ver = [AzureEngSemanticVersion]::ParseVersionString("1.0.0-post.1")
+        $ver.ToString() | Should -Be "1.0.0-post.1"
+        $ver.IsPostRelease | Should -BeFalse
+        $ver.PrereleaseLabel | Should -Be "post"
+    }
+}
+
+Describe "PEP 440 alternate post-release format normalization - Python convention" {
+    It "Should normalize hyphen separator '1.0.0-post1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0-post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0.post1"
+    }
+
+    It "Should normalize underscore separator '1.0.0_post1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0_post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0.post1"
+    }
+
+    It "Should normalize no-separator '1.0.0post1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0.post1"
+    }
+
+    It "Should normalize dot-number separator '1.0.0.post.1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post.1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0.post1"
+    }
+
+    It "Should normalize uppercase '1.0.0.POST1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.POST1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0.post1"
+    }
+
+    It "Should normalize implicit post number '1.0.0.post' to '1.0.0.post0'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.ToString() | Should -Be "1.0.0.post0"
+    }
+
+    It "Should normalize implicit post number with hyphen '1.0.0-post' to '1.0.0.post0'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0-post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.ToString() | Should -Be "1.0.0.post0"
+    }
+
+    It "Should normalize implicit post number with underscore '1.0.0_post' to '1.0.0.post0'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0_post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.ToString() | Should -Be "1.0.0.post0"
+    }
+
+    It "Should normalize implicit post number with no separator '1.0.0post' to '1.0.0.post0'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.ToString() | Should -Be "1.0.0.post0"
+    }
+
+    It "Should normalize implicit prerelease post number '1.0.0b2.post' to '1.0.0b2.post0'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2.post")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.PrereleaseLabel | Should -Be "b"
+        $ver.PrereleaseNumber | Should -Be 2
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 0
+        $ver.ToString() | Should -Be "1.0.0b2.post0"
+    }
+
+    It "Should normalize prerelease hyphen separator '1.0.0b2-post1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2-post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.PrereleaseLabel | Should -Be "b"
+        $ver.PrereleaseNumber | Should -Be 2
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0b2.post1"
+    }
+
+    It "Should normalize prerelease underscore separator '1.0.0b2_post1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2_post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.PrereleaseLabel | Should -Be "b"
+        $ver.PrereleaseNumber | Should -Be 2
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0b2.post1"
+    }
+
+    It "Should normalize prerelease no-separator '1.0.0b2post1' to canonical form" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2post1")
+        $ver | Should -Not -BeNullOrEmpty
+        $ver.PrereleaseLabel | Should -Be "b"
+        $ver.PrereleaseNumber | Should -Be 2
+        $ver.IsPostRelease | Should -BeTrue
+        $ver.PostReleaseNumber | Should -Be 1
+        $ver.ToString() | Should -Be "1.0.0b2.post1"
+    }
+}
+
+Describe "Post-release version ToString round-trip - Python convention" {
+    It "Should round-trip GA post-release '1.0.0.post1'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post1")
+        $ver.ToString() | Should -Be "1.0.0.post1"
+    }
+
+    It "Should round-trip patch version post-release '1.2.3.post5'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.2.3.post5")
+        $ver.ToString() | Should -Be "1.2.3.post5"
+    }
+
+    It "Should round-trip beta prerelease post-release '1.0.0b2.post1'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2.post1")
+        $ver.ToString() | Should -Be "1.0.0b2.post1"
+    }
+
+    It "Should round-trip alpha prerelease post-release '2.0.0a20201208001.post2'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("2.0.0a20201208001.post2")
+        $ver.ToString() | Should -Be "2.0.0a20201208001.post2"
+    }
+
+    It "Should normalize implicit post-release '1.0.0.post' to '1.0.0.post0'" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post")
+        $ver.ToString() | Should -Be "1.0.0.post0"
+    }
+}
+
+Describe "Post-release version sorting - Python convention" {
+    BeforeAll {
+        $global:Language = "python"
+    }
+
+    AfterAll {
+        $global:Language = ""
+    }
+
+    It "Should sort GA post-releases after GA and before next patch" {
+        $versions = @(
+            "1.0.1",
+            "1.0.0.post2",
+            "1.0.0",
+            "1.0.0.post1"
+        )
+        $expectedSort = @(
+            "1.0.1",
+            "1.0.0.post2",
+            "1.0.0.post1",
+            "1.0.0"
+        )
+        $sort = [AzureEngSemanticVersion]::SortVersionStrings($versions)
+        for ($i = 0; $i -lt $expectedSort.Count; $i++) {
+            $sort[$i] | Should -Be $expectedSort[$i]
+        }
+    }
+
+    It "Should sort prerelease post-releases after prerelease and before next prerelease" {
+        $versions = @(
+            "1.0.0",
+            "1.0.0b2",
+            "1.0.0b1.post1",
+            "1.0.0b1"
+        )
+        $expectedSort = @(
+            "1.0.0",
+            "1.0.0b2",
+            "1.0.0b1.post1",
+            "1.0.0b1"
+        )
+        $sort = [AzureEngSemanticVersion]::SortVersionStrings($versions)
+        for ($i = 0; $i -lt $expectedSort.Count; $i++) {
+            $sort[$i] | Should -Be $expectedSort[$i]
+        }
+    }
+
+    It "Should sort mixed versions with post-releases correctly" {
+        $versions = @(
+            "2.0.0",
+            "1.0.0.post1",
+            "2.0.0b1",
+            "1.0.0",
+            "2.0.0b1.post1",
+            "2.0.0.post1",
+            "1.0.1"
+        )
+        $expectedSort = @(
+            "2.0.0.post1",
+            "2.0.0",
+            "2.0.0b1.post1",
+            "2.0.0b1",
+            "1.0.1",
+            "1.0.0.post1",
+            "1.0.0"
+        )
+        $sort = [AzureEngSemanticVersion]::SortVersionStrings($versions)
+        for ($i = 0; $i -lt $expectedSort.Count; $i++) {
+            $sort[$i] | Should -Be $expectedSort[$i]
+        }
+    }
+
+    It "Should sort implicit post-release (post0) equivalently to explicit post0" {
+        $versions = @(
+            "1.0.0.post1",
+            "1.0.0",
+            "1.0.0.post0"
+        )
+        $expectedSort = @(
+            "1.0.0.post1",
+            "1.0.0.post0",
+            "1.0.0"
+        )
+        $sort = [AzureEngSemanticVersion]::SortVersionStrings($versions)
+        for ($i = 0; $i -lt $expectedSort.Count; $i++) {
+            $sort[$i] | Should -Be $expectedSort[$i]
+        }
+    }
+}
+
+Describe "Post-release version increment - Python convention" {
+    It "Should increment GA post-release '1.0.0.post1' to next prerelease" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post1")
+        $ver.IncrementAndSetToPrerelease()
+        $ver.ToString() | Should -Be "1.1.0b1"
+    }
+
+    It "Should increment beta post-release '1.0.0b2.post1' to next prerelease number" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0b2.post1")
+        $ver.IncrementAndSetToPrerelease()
+        $ver.ToString() | Should -Be "1.0.0b3"
+    }
+
+    It "Should increment zero-major post-release '0.1.0.post1' to next minor" {
+        $ver = [AzureEngSemanticVersion]::ParsePythonVersionString("0.1.0.post1")
+        $ver.IncrementAndSetToPrerelease()
+        $ver.ToString() | Should -Be "0.2.0"
+    }
+}
diff --git a/eng/common-tests/copy-docs-to-blobstorage.Tests.ps1 b/eng/common-tests/copy-docs-to-blobstorage.Tests.ps1
new file mode 100644
index 00000000000..d7f16ace2f3
--- /dev/null
+++ b/eng/common-tests/copy-docs-to-blobstorage.Tests.ps1
@@ -0,0 +1,181 @@
+Import-Module Pester
+
+BeforeAll {
+    $ExitOnError = 0
+    . $PSScriptRoot/../common/scripts/copy-docs-to-blobstorage.ps1 -DocLocation "/tmp" -ExitOnError 0
+    # common.ps1 sets $Language = "Unknown" in this scope. Override it to "python"
+    # so AzureEngSemanticVersion uses the Python regex (with post-release support).
+    $Language = "python"
+}
+
+Describe "ToSemVer - standard versions" {
+    It "Should parse GA version '1.0.0'" {
+        $v = ToSemVer "1.0.0"
+        $v | Should -Not -BeNullOrEmpty
+        $v.Major | Should -Be 1
+        $v.Minor | Should -Be 0
+        $v.Patch | Should -Be 0
+        $v.IsPrerelease | Should -BeFalse
+        $v.IsPostRelease | Should -BeFalse
+    }
+
+    It "Should parse prerelease version '1.0.0-beta.1'" {
+        $v = ToSemVer "1.0.0-beta.1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.Major | Should -Be 1
+        $v.PrereleaseLabel | Should -Be "beta"
+        $v.PrereleaseNumber | Should -Be 1
+        $v.IsPrerelease | Should -BeTrue
+        $v.IsPostRelease | Should -BeFalse
+    }
+
+    It "Should return null for invalid version" {
+        $v = ToSemVer "notaversion"
+        $v | Should -BeNullOrEmpty
+    }
+}
+
+Describe "ToSemVer - Python post-release versions" {
+    It "Should parse Python beta version '1.0.0b2'" {
+        
+        $v = ToSemVer "1.0.0b2"
+        $v | Should -Not -BeNullOrEmpty
+        $v.PrereleaseLabel | Should -Be "b"
+        $v.PrereleaseNumber | Should -Be 2
+        $v.IsPrerelease | Should -BeTrue
+        $v.IsPostRelease | Should -BeFalse
+    }
+
+    It "Should parse GA post-release '1.0.0.post1' as non-prerelease" {
+        
+        $v = ToSemVer "1.0.0.post1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.Major | Should -Be 1
+        $v.Minor | Should -Be 0
+        $v.Patch | Should -Be 0
+        $v.IsPrerelease | Should -BeFalse
+        $v.IsPostRelease | Should -BeTrue
+        $v.PostReleaseNumber | Should -Be 1
+    }
+
+    It "Should parse beta post-release '1.0.0b2.post1' as prerelease" {
+        
+        $v = ToSemVer "1.0.0b2.post1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.PrereleaseLabel | Should -Be "b"
+        $v.PrereleaseNumber | Should -Be 2
+        $v.IsPrerelease | Should -BeTrue
+        $v.IsPostRelease | Should -BeTrue
+        $v.PostReleaseNumber | Should -Be 1
+    }
+
+    It "Should normalize hyphen-separated '1.0.0-post1' as post-release" {
+        
+        $v = ToSemVer "1.0.0-post1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.IsPostRelease | Should -BeTrue
+        $v.PostReleaseNumber | Should -Be 1
+        $v.IsPrerelease | Should -BeFalse
+    }
+
+    It "Should normalize underscore-separated '1.0.0_post1' as post-release" {
+        
+        $v = ToSemVer "1.0.0_post1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.IsPostRelease | Should -BeTrue
+        $v.PostReleaseNumber | Should -Be 1
+        $v.IsPrerelease | Should -BeFalse
+    }
+
+    It "Should normalize no-separator '1.0.0post1' as post-release" {
+        
+        $v = ToSemVer "1.0.0post1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.IsPostRelease | Should -BeTrue
+        $v.PostReleaseNumber | Should -Be 1
+        $v.IsPrerelease | Should -BeFalse
+    }
+
+    It "Should parse post-release with higher number '1.0.0.post15'" {
+        
+        $v = ToSemVer "1.0.0.post15"
+        $v | Should -Not -BeNullOrEmpty
+        $v.IsPostRelease | Should -BeTrue
+        $v.PostReleaseNumber | Should -Be 15
+    }
+}
+
+Describe "ToSemVer - non-Python '1.0.0-post1' is prerelease, not post-release" {
+    It "Should treat '-post' as a prerelease label for non-Python languages" {
+        $Language = ""
+        $v = ToSemVer "1.0.0-post1"
+        $v | Should -Not -BeNullOrEmpty
+        $v.PrereleaseLabel | Should -Be "post"
+        $v.IsPrerelease | Should -BeTrue
+        $v.IsPostRelease | Should -BeFalse
+    }
+}
+
+Describe "Sort-Versions - Python post-release sorting" {
+    It "Should sort post-release after base GA version" {
+        
+        $sorted = Sort-Versions -VersionArray @("1.0.0", "1.0.0.post1")
+        $sorted.RawVersionsList[0] | Should -Be "1.0.0.post1"
+        $sorted.RawVersionsList[1] | Should -Be "1.0.0"
+    }
+
+    It "Should sort multiple post-releases in descending order" {
+        
+        $sorted = Sort-Versions -VersionArray @("1.0.0", "1.0.0.post1", "1.0.0.post2")
+        $sorted.RawVersionsList[0] | Should -Be "1.0.0.post2"
+        $sorted.RawVersionsList[1] | Should -Be "1.0.0.post1"
+        $sorted.RawVersionsList[2] | Should -Be "1.0.0"
+    }
+
+    It "Should sort post-release between base version and next version" {
+        
+        $sorted = Sort-Versions -VersionArray @("2.0.0", "1.0.0.post1", "1.0.0")
+        $sorted.RawVersionsList[0] | Should -Be "2.0.0"
+        $sorted.RawVersionsList[1] | Should -Be "1.0.0.post1"
+        $sorted.RawVersionsList[2] | Should -Be "1.0.0"
+    }
+
+    It "Should sort mixed versions with post-releases and prereleases" {
+        
+        $sorted = Sort-Versions -VersionArray @("1.0.0", "1.0.0.post1", "1.0.0b1", "2.0.0")
+        $sorted.RawVersionsList[0] | Should -Be "2.0.0"
+        $sorted.RawVersionsList[1] | Should -Be "1.0.0.post1"
+        $sorted.RawVersionsList[2] | Should -Be "1.0.0"
+        $sorted.RawVersionsList[3] | Should -Be "1.0.0b1"
+    }
+}
+
+Describe "Sort-Versions - Python post-release LatestGA/LatestPreview classification" {
+    It "Should classify GA post-release as LatestGA, not LatestPreview" {
+        
+        $sorted = Sort-Versions -VersionArray @("1.0.0", "1.0.0.post1")
+        $sorted.LatestGAPackage | Should -Be "1.0.0.post1"
+        $sorted.LatestPreviewPackage | Should -Be ""
+    }
+
+    It "Should not set LatestPreview for GA post-release when newer GA exists" {
+        
+        $sorted = Sort-Versions -VersionArray @("2.0.0", "1.0.0.post1", "1.0.0")
+        $sorted.LatestGAPackage | Should -Be "2.0.0"
+        $sorted.LatestPreviewPackage | Should -Be ""
+    }
+
+    It "Should set LatestPreview when prerelease is newer than GA post-release" {
+        
+        $sorted = Sort-Versions -VersionArray @("1.0.0", "1.0.0.post1", "2.0.0b1")
+        $sorted.LatestGAPackage | Should -Be "1.0.0.post1"
+        $sorted.LatestPreviewPackage | Should -Be "2.0.0b1"
+    }
+
+    It "Should treat beta post-release as prerelease for LatestGA/LatestPreview" {
+        
+        $sorted = Sort-Versions -VersionArray @("1.0.0b2", "1.0.0b2.post1")
+        $sorted.LatestGAPackage | Should -Be ""
+        $sorted.LatestPreviewPackage | Should -Be "1.0.0b2.post1"
+    }
+}
diff --git a/eng/common/scripts/ChangeLog-Operations.ps1 b/eng/common/scripts/ChangeLog-Operations.ps1
index 170157ff511..98126a695c2 100644
--- a/eng/common/scripts/ChangeLog-Operations.ps1
+++ b/eng/common/scripts/ChangeLog-Operations.ps1
@@ -3,6 +3,7 @@
 . "${PSScriptRoot}\SemVer.ps1"
 
 $RELEASE_TITLE_REGEX = "(?<releaseNoteTitle>^\#+\s+(?<version>$([AzureEngSemanticVersion]::SEMVER_REGEX))(\s+(?<releaseStatus>\(.+\))))"
+$PYTHON_RELEASE_TITLE_REGEX = "(?<releaseNoteTitle>^\#+\s+(?<version>$([AzureEngSemanticVersion]::PYTHON_SEMVER_REGEX))(\s+(?<releaseStatus>\(.+\))))"
 $SECTION_HEADER_REGEX_SUFFIX = "##\s(?<sectionName>.*)"
 $CHANGELOG_UNRELEASED_STATUS = "(Unreleased)"
 $CHANGELOG_DATE_FORMAT = "yyyy-MM-dd"
@@ -62,11 +63,13 @@ function Get-ChangeLogEntriesFromContent {
   $changeLogEntries | Add-Member -NotePropertyName "InitialAtxHeader" -NotePropertyValue $initialAtxHeader
   $releaseTitleAtxHeader = $initialAtxHeader + "#"
   $headerLines = @()
+  $parseLanguage = (Get-Variable -Name "Language" -ValueOnly -ErrorAction "Ignore")
+  $titleRegex = if ($parseLanguage -eq "python") { $PYTHON_RELEASE_TITLE_REGEX } else { $RELEASE_TITLE_REGEX }
 
   try {
     # walk the document, finding where the version specifiers are and creating lists
     foreach ($line in $changeLogContent) {
-      if ($line -match $RELEASE_TITLE_REGEX) {
+      if ($line -match $titleRegex) {
         $changeLogEntry = [pscustomobject]@{
           ReleaseVersion = $matches["version"]
           ReleaseStatus  =  $matches["releaseStatus"]
diff --git a/eng/common/scripts/SemVer.ps1 b/eng/common/scripts/SemVer.ps1
index 689a70e778c..eeb7ab5f4ac 100644
--- a/eng/common/scripts/SemVer.ps1
+++ b/eng/common/scripts/SemVer.ps1
@@ -30,11 +30,20 @@ class AzureEngSemanticVersion : IComparable {
   [bool] $IsSemVerFormat
   [string] $DefaultPrereleaseLabel
   [string] $DefaultAlphaReleaseLabel
+  # For Python PEP440 post-release support only
+  [bool] $IsPostRelease
+  [int] $PostReleaseNumber
+  [string] $PostReleaseSeparator
 
   # Regex inspired but simplified from https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string
   # Validation: https://regex101.com/r/vkijKf/426
   static [string] $SEMVER_REGEX = "(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:(?<presep>-?)(?<prelabel>[a-zA-Z]+)(?:(?<prenumsep>\.?)(?<prenumber>[0-9]{1,8})(?:(?<buildnumsep>\.?)(?<buildnumber>\d{1,3}))?)?)?"
 
+  # Python PEP 440 post-release extension
+  # Handles all PEP 440 alternate formats: .postN, -postN, _postN, postN, .post.N, .post (implicit 0) (case-insensitive)
+  # Validation: https://regex101.com/r/rAdOg0/2
+  static [string] $PYTHON_SEMVER_REGEX = [AzureEngSemanticVersion]::SEMVER_REGEX + "(?:(?<postsep>[.\-_]?)(?<postword>(?i:post))\.?(?<postnum>\d+)?)?"
+
   static [AzureEngSemanticVersion] ParseVersionString([string] $versionString)
   {
     $version = [AzureEngSemanticVersion]::new($versionString)
@@ -47,19 +56,34 @@ class AzureEngSemanticVersion : IComparable {
 
   static [AzureEngSemanticVersion] ParsePythonVersionString([string] $versionString)
   {
-    $version = [AzureEngSemanticVersion]::ParseVersionString($versionString)
+    $previousLanguage = (Get-Variable -Name "Language" -ValueOnly -ErrorAction "Ignore")
+    $global:Language = "python"
+    $version = $null
+    try {
+      $version = [AzureEngSemanticVersion]::new($versionString)
+    }
+    finally {
+      $global:Language = $previousLanguage
+    }
 
-    if (!$version) {
+    if (!$version.IsSemVerFormat) {
       return $null
     }
-
-    $version.SetupPythonConventions()
     return $version
   }
   
   AzureEngSemanticVersion([string] $versionString)
   {
-    if ($versionString -match "^$([AzureEngSemanticVersion]::SEMVER_REGEX)$")
+    $parseLanguage = (Get-Variable -Name "Language" -ValueOnly -ErrorAction "Ignore")
+
+    if ($parseLanguage -eq "python") {
+      $parseRegex = [AzureEngSemanticVersion]::PYTHON_SEMVER_REGEX
+    }
+    else {
+      $parseRegex = [AzureEngSemanticVersion]::SEMVER_REGEX
+    }
+
+    if ($versionString -match "^${parseRegex}$")
     {
       $this.IsSemVerFormat = $true
       $this.RawVersion = $versionString
@@ -67,16 +91,28 @@ class AzureEngSemanticVersion : IComparable {
       $this.Minor = [int]$matches.Minor
       $this.Patch = [int]$matches.Patch
 
-      # If Language exists and is set to python setup the python conventions.
-      $parseLanguage = (Get-Variable -Name "Language" -ValueOnly -ErrorAction "Ignore")
+      $skipPrelabel = $false
       if ($parseLanguage -eq "python") {
         $this.SetupPythonConventions()
+        if ($matches['postword']) {
+          $this.IsPostRelease = $true
+          $this.PostReleaseNumber = if ($matches['postnum']) { [int]$matches['postnum'] } else { 0 }
+          $this.PostReleaseSeparator = ".post"
+        }
+        elseif ($matches['prelabel'] -and $matches['prelabel'] -ieq 'post') {
+          # Alternate PEP 440 forms like "1.0.0-post1" or "1.0.0post1" where the regex
+          # matched "post" as a prerelease label — reinterpret as post-release.
+          $this.IsPostRelease = $true
+          $this.PostReleaseNumber = [int]$matches['prenumber']
+          $this.PostReleaseSeparator = ".post"
+          $skipPrelabel = $true
+        }
       }
       else {
         $this.SetupDefaultConventions()
       }
 
-      if ($null -eq $matches['prelabel'])
+      if ($skipPrelabel -or $null -eq $matches['prelabel'])
       {
         $this.IsPrerelease = $false
         $this.VersionType = "GA"
@@ -141,6 +177,9 @@ class AzureEngSemanticVersion : IComparable {
           $versionString += $this.BuildNumberSeparator + $this.BuildNumber
       }
     }
+    if ($this.IsPostRelease) {
+      $versionString += $this.PostReleaseSeparator + $this.PostReleaseNumber
+    }
     return $versionString;
   }
 
@@ -150,6 +189,13 @@ class AzureEngSemanticVersion : IComparable {
       throw "Cannot increment releases tagged with azure pipelines build numbers"
     }
 
+    # Clear post-release state before incrementing
+    if ($this.IsPostRelease) {
+      $this.IsPostRelease = $false
+      $this.PostReleaseNumber = 0
+      $this.PostReleaseSeparator = ""
+    }
+
     if ($this.PrereleaseLabel)
     {
       $this.PrereleaseNumber++
@@ -239,12 +285,27 @@ class AzureEngSemanticVersion : IComparable {
     $ret = $thisPrereleaseNumber.CompareTo($otherPrereleaseNumber)
     if ($ret) { return $ret }
 
-    return ([int] $this.BuildNumber).CompareTo([int] $other.BuildNumber)
+    $ret = ([int] $this.BuildNumber).CompareTo([int] $other.BuildNumber)
+    if ($ret) { return $ret }
+
+    # Post-release versions sort after their base version
+    $thisPost = if ($this.IsPostRelease) { 1 } else { 0 }
+    $otherPost = if ($other.IsPostRelease) { 1 } else { 0 }
+    $ret = $thisPost.CompareTo($otherPost)
+    if ($ret) { return $ret }
+
+    return $this.PostReleaseNumber.CompareTo($other.PostReleaseNumber)
   }
 
   static [string[]] SortVersionStrings([string[]] $versionStrings)
   {
-    $versions = $versionStrings | ForEach-Object { [AzureEngSemanticVersion]::ParseVersionString($_) }
+    $parseLanguage = (Get-Variable -Name "Language" -ValueOnly -ErrorAction "Ignore")
+    if ($parseLanguage -eq "python") {
+      $versions = $versionStrings | ForEach-Object { [AzureEngSemanticVersion]::ParsePythonVersionString($_) }
+    }
+    else {
+      $versions = $versionStrings | ForEach-Object { [AzureEngSemanticVersion]::ParseVersionString($_) }
+    }
     $sortedVersions = [AzureEngSemanticVersion]::SortVersions($versions)
     return ($sortedVersions | ForEach-Object { $_.RawVersion })
   }
@@ -429,6 +490,64 @@ class AzureEngSemanticVersion : IComparable {
       Write-Host "Error: version string did not correctly increment. Expected: $expected, Actual: $version"
     }
 
+    # Python post-release parsing tests
+    $postVerString = "1.0.0.post1"
+    $postVer = [AzureEngSemanticVersion]::ParsePythonVersionString($postVerString)
+    if ($postVer.Major -ne 1 -or $postVer.Minor -ne 0 -or $postVer.Patch -ne 0 -or `
+        !$postVer.IsPostRelease -or $postVer.PostReleaseNumber -ne 1 -or $postVer.IsPrerelease) {
+      Write-Host "Error: Didn't correctly parse python post-release string $postVerString"
+    }
+    if ($postVerString -ne $postVer.ToString()) {
+      Write-Host "Error: post-release string did not correctly round trip with ToString. Expected: $($postVerString), Actual: $($postVer)"
+    }
+
+    # Implicit post-release number (PEP 440: 1.0.0.post == 1.0.0.post0)
+    $implicitPostVerString = "1.0.0.post"
+    $implicitPostVer = [AzureEngSemanticVersion]::ParsePythonVersionString($implicitPostVerString)
+    if ($null -eq $implicitPostVer -or !$implicitPostVer.IsSemVerFormat) {
+      Write-Host "Error: Failed to parse implicit post-release string $implicitPostVerString"
+    }
+    elseif ($implicitPostVer.Major -ne 1 -or $implicitPostVer.Minor -ne 0 -or $implicitPostVer.Patch -ne 0 -or `
+            !$implicitPostVer.IsPostRelease -or $implicitPostVer.PostReleaseNumber -ne 0) {
+      Write-Host "Error: Didn't correctly parse implicit post-release string $implicitPostVerString"
+    }
+    $expected = "1.0.0.post0"
+    if ($expected -ne $implicitPostVer.ToString()) {
+      Write-Host "Error: implicit post-release did not normalize. Expected: $expected, Actual: $($implicitPostVer)"
+    }
+
+    # Prerelease + post-release
+    $preBetaPostString = "1.0.0b2.post1"
+    $preBetaPost = [AzureEngSemanticVersion]::ParsePythonVersionString($preBetaPostString)
+    if ($preBetaPost.Major -ne 1 -or $preBetaPost.Minor -ne 0 -or $preBetaPost.Patch -ne 0 -or `
+        $preBetaPost.PrereleaseLabel -ne "b" -or $preBetaPost.PrereleaseNumber -ne 2 -or `
+        !$preBetaPost.IsPostRelease -or $preBetaPost.PostReleaseNumber -ne 1) {
+      Write-Host "Error: Didn't correctly parse python prerelease post-release string $preBetaPostString"
+    }
+    if ($preBetaPostString -ne $preBetaPost.ToString()) {
+      Write-Host "Error: prerelease post-release string did not correctly round trip with ToString. Expected: $($preBetaPostString), Actual: $($preBetaPost)"
+    }
+
+    # Post-release alternate separators normalize to canonical form
+    $expectedNormalized = "1.0.0.post1"
+    foreach ($altVerString in @("1.0.0-post1", "1.0.0_post1", "1.0.0post1")) {
+      $parsed = [AzureEngSemanticVersion]::ParsePythonVersionString($altVerString)
+      if ($null -eq $parsed -or !$parsed.IsPostRelease -or $parsed.PostReleaseNumber -ne 1) {
+        Write-Host "Error: Failed to parse alternate post-release format $altVerString"
+      }
+      if ($expectedNormalized -ne $parsed.ToString()) {
+        Write-Host "Error: Alternate post-release '$altVerString' did not normalize. Expected: $expectedNormalized, Actual: $($parsed)"
+      }
+    }
+
+    # Post-release increment clears post state
+    $postIncVer = [AzureEngSemanticVersion]::ParsePythonVersionString("1.0.0.post1")
+    $postIncVer.IncrementAndSetToPrerelease()
+    $expected = "1.1.0b1"
+    if ($expected -ne $postIncVer.ToString()) {
+      Write-Host "Error: post-release increment did not produce expected result. Expected: $expected, Actual: $($postIncVer)"
+    }
+
     Write-Host "QuickTests done"
   }
 }
\ No newline at end of file
diff --git a/eng/common/scripts/artifact-metadata-parsing.ps1 b/eng/common/scripts/artifact-metadata-parsing.ps1
index 9a45855c0ec..2bc1713e191 100644
--- a/eng/common/scripts/artifact-metadata-parsing.ps1
+++ b/eng/common/scripts/artifact-metadata-parsing.ps1
@@ -1,6 +1,6 @@
 . (Join-Path $EngCommonScriptsDir SemVer.ps1)
 
-$SDIST_PACKAGE_REGEX = "^(?<package>.*)\-(?<versionstring>$([AzureEngSemanticVersion]::SEMVER_REGEX))"
+$SDIST_PACKAGE_REGEX = "^(?<package>.*)\-(?<versionstring>$([AzureEngSemanticVersion]::PYTHON_SEMVER_REGEX))"
 
 # Posts a github release for each item of the pkgList variable. Silently continue
 function CreateReleases($pkgList, $releaseApiUrl, $releaseSha) {
diff --git a/eng/common/scripts/copy-docs-to-blobstorage.ps1 b/eng/common/scripts/copy-docs-to-blobstorage.ps1
index 852945338e9..aa33a93f33c 100644
--- a/eng/common/scripts/copy-docs-to-blobstorage.ps1
+++ b/eng/common/scripts/copy-docs-to-blobstorage.ps1
@@ -12,56 +12,28 @@ param (
 
 . (Join-Path $PSScriptRoot common.ps1)
 
-# Regex inspired but simplified from https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string
-$SEMVER_REGEX = "^(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:-?(?<prelabel>[a-zA-Z-]*)(?:\.?(?<prenumber>0|[1-9]\d*))?)?$"
-
 function ToSemVer($version){
-    if ($version -match $SEMVER_REGEX)
-    {
-        if(-not $matches['prelabel']) {
-            # artifically provide these values for non-prereleases to enable easy sorting of them later than prereleases.
-            $prelabel = "zzz"
-            $prenumber = 999;
-            $isPre = $false;
-        }
-        else {
-            $prelabel = $matches["prelabel"]
-            $prenumber = 0
-
-            # some older packages don't have a prenumber, should handle this
-            if($matches["prenumber"]){
-                $prenumber = [int]$matches["prenumber"]
+    try {
+        $sv = [AzureEngSemanticVersion]::new($version)
+        if (!$sv.IsSemVerFormat) {
+            if ($ExitOnError) {
+                throw "Unable to convert $version to valid semver and hard exit on error is enabled. Exiting."
             }
-
-            $isPre = $true;
-        }
-
-        New-Object PSObject -Property @{
-            Major = [int]$matches['major']
-            Minor = [int]$matches['minor']
-            Patch = [int]$matches['patch']
-            PrereleaseLabel = $prelabel
-            PrereleaseNumber = $prenumber
-            IsPrerelease = $isPre
-            RawVersion = $version
+            return $null
         }
+        return $sv
     }
-    else
-    {
-        if ($ExitOnError)
-        {
+    catch {
+        if ($ExitOnError) {
             throw "Unable to convert $version to valid semver and hard exit on error is enabled. Exiting."
         }
-        else
-        {
-            return $null
-        }
+        return $null
     }
 }
 
 function SortSemVersions($versions)
 {
-    return $versions | Sort-Object -Property Major, Minor, Patch, PrereleaseLabel, PrereleaseNumber -Descending
+    return $versions | Sort-Object -Descending
 }
 
 function Sort-Versions
diff --git a/tools/spec-gen-sdk/src/utils/parseSemverVersionString.ts b/tools/spec-gen-sdk/src/utils/parseSemverVersionString.ts
index 936b1ec5be7..d3608bdfeca 100644
--- a/tools/spec-gen-sdk/src/utils/parseSemverVersionString.ts
+++ b/tools/spec-gen-sdk/src/utils/parseSemverVersionString.ts
@@ -29,6 +29,13 @@ export function parseSemverVersionString(
   // Copied from https://github.com/Azure/azure-sdk-tools/blob/efa8a15c81e4614f2071b82dd8ca4f6ce6076f7b/eng/common/scripts/SemVer.ps1#L36
   const SEMVER_REGEX =
    /(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:(?<presep>-?)(?<prelabel>[a-zA-Z]+)(?:(?<prenumsep>\.?)(?<prenumber>[0-9]{1,8})(?:(?<buildnumsep>\.?)(?<buildnumber>\d{1,3}))?)?)?/im;
+  // Python PEP 440 post-release extension: SEMVER_REGEX + optional post-release suffix.
+  // Handles all PEP 440 alternate formats: .postN, -postN, _postN, postN, .post.N, .post (implicit 0) (case-insensitive)
+  const PYTHON_SEMVER_REGEX =
+   /(?<major>0|[1-9]\d*)\.(?<minor>0|[1-9]\d*)\.(?<patch>0|[1-9]\d*)(?:(?<presep>-?)(?<prelabel>[a-zA-Z]+)(?:(?<prenumsep>\.?)(?<prenumber>[0-9]{1,8})(?:(?<buildnumsep>\.?)(?<buildnumber>\d{1,3}))?)?)?(?:(?<postsep>[.\-_]?)(?<postword>[pP][oO][sS][tT])\.?(?<postnum>\d+)?)?/im;
+
+  const isPython = language.toLowerCase() === 'python';
+  const parseRegex = isPython ? PYTHON_SEMVER_REGEX : SEMVER_REGEX;
   let prereleaseLabelSeparator: string | undefined;
   let prereleaseNumberSeparator: string | undefined;
   let buildNumberSeparator: string | undefined;
@@ -45,7 +52,10 @@ export function parseSemverVersionString(
   let prelabel: string | undefined;
   let isSemVerFormat: boolean | undefined;
   let rawVersion: string | undefined;
-  const matches = versionString.match(SEMVER_REGEX);
+  let isPostRelease: boolean | undefined;
+  let postReleaseNumber: string | undefined;
+  let postReleaseSeparator: string | undefined;
+  const matches = versionString.match(parseRegex);
   if (matches) {
     isSemVerFormat = true;
     rawVersion = versionString;
@@ -53,8 +63,7 @@ export function parseSemverVersionString(
     minor = matches && matches.groups && matches.groups.minor;
     patch = matches && matches.groups && matches.groups.patch;
     // If Language exists and is set to python setup the python conventions.
-    const parseLanguage = 'python';
-    if (parseLanguage === language.toLowerCase()) {
+    if (isPython) {
       // Python uses no separators and 'b' for beta so this sets up the the object to work with those conventions
       prereleaseLabelSeparator = prereleaseNumberSeparator = buildNumberSeparator = '';
       defaultPrereleaseLabel = 'b';
@@ -68,8 +77,28 @@ export function parseSemverVersionString(
       defaultAlphaReleaseLabel = 'alpha';
     }
 
+    let skipPrelabel = false;
+
+    // Python PEP 440 post-release detection
+    if (isPython) {
+      const postword = matches?.groups?.postword;
+      if (postword) {
+        // Case A: explicit post-release suffix (e.g., "1.0.0.post1", "1.0.0b2.post1")
+        isPostRelease = true;
+        postReleaseNumber = matches?.groups?.postnum ?? '0';
+        postReleaseSeparator = '.post';
+      } else if (matches?.groups?.prelabel && matches.groups.prelabel.toLowerCase() === 'post') {
+        // Case B: "post" captured as prelabel (e.g., "1.0.0-post1", "1.0.0post1")
+        // Reinterpret as post-release, not prerelease
+        isPostRelease = true;
+        postReleaseNumber = matches?.groups?.prenumber ?? '0';
+        postReleaseSeparator = '.post';
+        skipPrelabel = true;
+      }
+    }
+
     prelabel = matches && matches.groups && matches.groups.prelabel;
-    if (!prelabel) {
+    if (skipPrelabel || !prelabel) {
       prereleaseLabel = 'zzz';
       prereleaseNumber = '99999999';
       isPrerelease = false;
@@ -111,7 +140,10 @@ export function parseSemverVersionString(
     rawVersion,
     isSemVerFormat,
     defaultPrereleaseLabel,
-    defaultAlphaReleaseLabel
+    defaultAlphaReleaseLabel,
+    isPostRelease,
+    postReleaseNumber,
+    postReleaseSeparator
   };
 }
 
@@ -132,4 +164,7 @@ type ParseVersion = {
   prelabel: string | undefined;
   isSemVerFormat: boolean | undefined;
   rawVersion: string | undefined;
+  isPostRelease: boolean | undefined;
+  postReleaseNumber: string | undefined;
+  postReleaseSeparator: string | undefined;
 };
diff --git a/tools/spec-gen-sdk/test/utils/parseSemverVersionString.test.ts b/tools/spec-gen-sdk/test/utils/parseSemverVersionString.test.ts
index 297e5517535..40dc48553cd 100644
--- a/tools/spec-gen-sdk/test/utils/parseSemverVersionString.test.ts
+++ b/tools/spec-gen-sdk/test/utils/parseSemverVersionString.test.ts
@@ -95,4 +95,53 @@ describe('parseSemverVersionString', () => {
       }),
     ).toBeTruthy();
   });
+
+  it('Parse a standard Python post-release version', () => {
+    const parsedVersion = parseSemverVersionString('1.0.0.post1', 'Python');
+    expect(parsedVersion?.isSemVerFormat).toEqual(true);
+    expect(parsedVersion?.major).toEqual('1');
+    expect(parsedVersion?.minor).toEqual('0');
+    expect(parsedVersion?.patch).toEqual('0');
+    expect(parsedVersion?.isPostRelease).toEqual(true);
+    expect(parsedVersion?.postReleaseNumber).toEqual('1');
+    expect(parsedVersion?.postReleaseSeparator).toEqual('.post');
+    expect(parsedVersion?.isPrerelease).toEqual(false);
+    expect(parsedVersion?.versionType).toEqual('GA');
+  });
+
+  it('Parse a Python post-release with implicit number', () => {
+    const parsedVersion = parseSemverVersionString('1.0.0.post', 'Python');
+    expect(parsedVersion?.isPostRelease).toEqual(true);
+    expect(parsedVersion?.postReleaseNumber).toEqual('0');
+    expect(parsedVersion?.isPrerelease).toEqual(false);
+    expect(parsedVersion?.versionType).toEqual('GA');
+  });
+
+  it('Parse a Python prerelease + post-release version', () => {
+    const parsedVersion = parseSemverVersionString('1.0.0b2.post1', 'Python');
+    expect(parsedVersion?.isPrerelease).toEqual(true);
+    expect(parsedVersion?.prereleaseLabel).toEqual('b');
+    expect(parsedVersion?.prereleaseNumber).toEqual('2');
+    expect(parsedVersion?.isPostRelease).toEqual(true);
+    expect(parsedVersion?.postReleaseNumber).toEqual('1');
+    expect(parsedVersion?.versionType).toEqual('Beta');
+  });
+
+  it('Parse Python post-release with alternate separators', () => {
+    for (const ver of ['1.0.0-post1', '1.0.0_post1', '1.0.0post1']) {
+      const parsedVersion = parseSemverVersionString(ver, 'Python');
+      expect(parsedVersion?.isPostRelease).toEqual(true);
+      expect(parsedVersion?.postReleaseNumber).toEqual('1');
+      expect(parsedVersion?.isPrerelease).toEqual(false);
+      expect(parsedVersion?.versionType).toEqual('GA');
+    }
+  });
+
+  it('Non-Python language treats "post" as prerelease label, not post-release', () => {
+    const parsedVersion = parseSemverVersionString('1.0.0-post1', 'JavaScript');
+    expect(parsedVersion?.isPostRelease).toBeUndefined();
+    expect(parsedVersion?.isPrerelease).toEqual(true);
+    expect(parsedVersion?.versionType).toEqual('Beta');
+    expect(parsedVersion?.prereleaseLabel).toEqual('post');
+  });
 });