Feature request: Support for copying the Format instance

[croshchupkin]

Is it possible to add the subject? So that when we have a "general" format for the data processed in a loop, we could e.g. assign a separate Format instance to the cells that we want to write the hyperlinks into.

[jmcnamara]

Hi Constantin,

Yes, that should be possible. I actually had a format.copy() method in a previous version of this module but didn't port it to this version because no-one seemed to use it.

Could you give me a small code example of what you are trying/would like to do.

John

[croshchupkin]

@classmethod
def write(cls, data, workbook, worksheet, cell_address, cell_format=None):
    # snip
    if cell_format:
        cell_format = cell_format.copy()
        cell_format.set_underline()
        cell_format.set_color('blue')
    # snip
    return worksheet.write(
         cell_address,
         value, # this is a URL
         cell_format,
         u'ссылка')

[jmcnamara]

I'll leave that as a feature request and add it in if it gets a few +1s.

In the meantime, URLs get a default blue underline format from XlsxWriter if none is supplied. So you may be able to use that feature instead:

import xlsxwriter

workbook = xlsxwriter.workbook.Workbook('url.xlsx')
worksheet = workbook.add_worksheet()

worksheet.set_column('A:A', 20)

worksheet.write(
         'A1',
         'http://www.python.org',
         None, # Note. No format.
         u'Some text')

workbook.close()

[croshchupkin]

OK, thanks for the info. But I don't think this will be the only use case when I may need to apply additional formatting to a separate cell. Also, in LibreOffice, the link is not underlined (although I don't think it's crucial for presenting the spreadsheet to our client). So I agree that this issue shouldn't be closed.
Again, thank you for your swift replies.

[ifmihai]

👍 for sure

I think it would be useful to have a format1.update(source) method also, to update format1 with a dict or another format

or format1.combine(format2), to return a new combined format (to not change format1)

Working with data and pandas, I see myself almost each time thinking about how I could combine formats for different columns and rows

UPDATE1
After investigating the structure of a format,
seeing the underlying dict there,
i'm not sure how or if .update() or .combine() would work
in this case, .copy() would be the only way, so 👍

[jmcnamara]

Thanks for the 👍

Format copying and updating will be handled as part of #111 "Feature request: Separate data and formatting".

I just need to carve out the time to tackle that. :-)

[ifmihai]

Just for reference I guess,

I implemented in a rush these 2 functions, format_copy() and format_update()
maybe other people need it for fast results until #111 is available

from copy import copy

def format_copy(format):
    '''returns a copy of the format
    '''
    return copy(format)

def format_update(format, d, inplace=False):
    '''updates format with a dict d
    format: the format
    d: dict with new attributes
    inplace: bool
             if format should be modified or not
    '''
    if inplace:
        fmt = format
    else:
        fmt = format_copy(format)

    fmt.__dict__.update(d)

    return fmt

UPDATE
unfortunately, these functions don't work, I don't understand why for now,
format_copy() creates unreadable content for excel
format_update() generates Exception IndexError: list assignment index out of range in self._prepare_formats()

if I get them to work, I will update this comment

[ifmihai]

@jmcnamara
I'm no expert, and I understand #111 just intuitively now,
but,

for my needs, working with pandas mostly,
having these 2 functions is what i need in all my cases

but maybe #111 is way better, I don't know

just wanted to say: "take your time with #111"
:)

[jmcnamara]

unfortunately, these functions don't work, I don't understand why for now

Formats have to be created via the workbook.add_format() method so that the workbook object can track them and give the formats an index number for the format, fonts, fills and other properties prior to saving and so that it ca remove duplicates and do some other operations required by Excel.

So a straight copy won't work. Copying properties from 2 format objects created with add_format() should work though.

[ifmihai]

What do you mean: "copying properties from 2 format objects" ?
I don't understand

maybe two objects of format type?

so then I should first create a new workbook.add_format(), then copy, then return it?

[sontek]

+1 to copying formats, my code is out of hand from duplicating the same things over and over again

[creeson]

Copying formats would be a huge help to me.

[cimarronm]

👍 would like to see this

@jmcnamara I just recently discovered xlsxwriter...excellent work

[andrew-zenefits]

+1 for copying formats