datetime_df

import pandas as pd
import numpy as np

data = [['A001', '3/2/1950','1/1/2010','1/1/2010','','','','','','','','','',''],
        ['A001', '3/2/1950','','','','1/1/2010','','','','','','','',''],
        ['A001', '3/2/1950','','','','1/1/2010','1/1/2010','','','','','','',''],
        ['A001', '3/2/1950','','','','','','1/1/2010','','','','','',''],
        ['A001', '3/2/1950','','','','','','','1/1/2010','1/1/2010','1/1/2010','1/1/2010','',''],
        ['A001', '3/2/1950','','','','','','','','','','','1/1/2010',''],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A001', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','0107-01-06','1/1/2010','','','','','','','','','',''],
        ['A002', '3/2/1950','','','','1/1/2010','','','','','','','',''],
        ['A002', '3/2/1950','','','','1/1/2010','1/1/2010','','','','','','',''],
        ['A002', '3/2/1950','','','','','','1/1/2010','','','','','',''],
        ['A002', '3/2/1950','','','','','','','1/1/2010','1/1/2010','1/1/2010','1/1/2010','',''],
        ['A002', '3/2/1950','','','','','','','','','','','1/1/2010',''],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','1/1/2010'],
        ['A002', '3/2/1950','','','','','','','','','','','','0107-01-06']]

df = pd.DataFrame(data,columns=['patient_ID','DateOfBirth','date_1','date_2','date_3','date_4','date_5','date_6','date_7','date_8','date_9','date_10','date_11','date_12',])

# insert empty Fail column to identify date errors
df.insert(loc=0, column='Fail', value="")

# replace all blanks with np.NaN
df.replace(r"^s*$", np.nan, regex=True, inplace = True)

# get list of date columns
cols = list(df)
date_cols = cols[2:]

# create empty dict
dfs = {}

# iterate over date columns to identify which columns contain invalid dates & add to dfs
for col in df[date_cols]:
    try:
        df[col] = df[col].apply(pd.to_datetime, errors='raise')
    except:
        print("%s column contains invalid date" % col)
        dfs[col] = df[col]