Convert object to datetime stamp in python pandas. Where day has no leading zero

Question

I cant seem to convert this dataframe column to a datetime stamp.

Date_Last_Modified
January 1 2021 7:36:32 pm
January 11 2021 7:36:32 pm... ect

The dtype is an object and the %e does not work nor does the %-d work. this is my command.

df['Date_Last_Modified'] = pd.to_datetime(df['Date_Last_Modified'], format='%B %d %Y %I:%M:%S %p')

Here is the error

ValueError: time data 'Date Last Modified' does not match format '%B %d %Y %I:%M:%S %p' (match)

or

df['Date_Last_Modified'] = pd.to_datetime(df['Date_Last_Modified'], format='%B %e %Y %I:%M:%S %p')

ValueError: 'e' is a bad directive in format '%B %e %Y %I:%M:%S %p'

Answer 1

If want test what values are wrong add errors='coerce' and test missing values:

print (df[pd.to_datetime(df['Date_Last_Modified'], 
                         format='%B %d %Y %I:%M:%S %p', 
                         errors='coerce').isna()])

Here is simplier solution - first converted bad values to NaNs by parameter errors='coerce' and then using DataFrame.dropna remove this rows:

df['Date_Last_Modified'] =  pd.to_datetime(df['Date_Last_Modified'], 
                                           format='%B %d %Y %I:%M:%S %p', 
                                           errors='coerce')

df = df.dropna(subset=['Date_Last_Modified'])