[Python] ValueError: time data does not match format '%m/%d/%Y %H:%M:%S.%f'

I am writing this code to change the type of "Gmt time" column. But, I give "ValueError: time data does not match format ". How could I convert to float or someother types except Object and string?

My code is:
​

path= '/content/drive/MyDrive/H1_ASK_Raw.csv'
dateparse = lambda dates: pd.datetime.strptime(dates, '%m/%d/%Y %H:%M:%S.%f')
df = pd.read_csv(path,sep=',', index_col='Date', parse_dates=['Gmt time'], date_parser=dateparse).fillna(0)
df.head()

I get the below Error:
​

TypeError Traceback (most recent call last)
/usr/local/lib/python3.7/dist-packages/pandas/io/parsers/base_parser.py in converter(*date_cols)
1038 result = tools.to_datetime(
-> 1039 date_parser(*date_cols), errors="ignore", cache=cache_dates
1040 )

18 frames
TypeError: strptime() argument 1 must be str, not numpy.ndarray

During handling of the above exception, another exception occurred:

ValueError Traceback (most recent call last)
ValueError: time data '05.05.2003 00:00:00.000' does not match format '%m/%d/%Y %H:%M:%S'

During handling of the above exception, another exception occurred:

ValueError Traceback (most recent call last)
/usr/lib/python3.7/_strptime.py in _strptime(data_string, format)
357 if not found:
358 raise ValueError("time data %r does not match format %r" %
--> 359 (data_string, format))
360 if len(data_string) != found.end():
361 raise ValueError("unconverted data remains: %s" %

ValueError: time data '05.05.2003 00:00:00.000' does not match format '%m/%d/%Y %H:%M:%S.%f'

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