Update nab.py (#167)

#line 87 gives TypeError: int() argument must be a string, a bytes-like object or a real number, not 'Timedelta'.

Co-authored-by: Tian Lan <31748898+Emerald01@users.noreply.github.com>

Author: Rohith-Papani

ts_datasets/ts_datasets/anomaly/nab.py

@@ -83,8 +83,8 @@ def __init__(self, subset="all", rootdir=None):
             if len(df["timestamp"][df["timestamp"].diff() == datetime.timedelta(0)]) != 0:
                 df = df.drop_duplicates(subset="timestamp", keep="first")
                 logger.warning(f"Time series {csv} (index {i}) has timestamp duplicates. Kept first values.")
-
-            all_dt = np.unique(np.diff(df["timestamp"])).astype(np.int64)
+                
+            all_dt = np.unique(np.diff(df["timestamp"]))
             gcd_dt = all_dt[0]
             for dt in all_dt[1:]:
                 gcd_dt = np.gcd(gcd_dt, dt)