python 3.x - Mixed date formats dd/mm/yyyy and d/m/y in pandas -

i have dataframe mixed date formats in column. of in format dd/mm/yyyy , of in format d/m/y. how can set column datetime applying appropriate format depending on value of cell? reading csv file:

dayofweek,date friday,22/05/2015 friday,10/2/12 friday,10/10/14 friday,21/10/2011 friday,8/7/11 

df = pd.read_csv('dates.txt', parse_dates=['date'], dayfirst=true) df.info()  <class 'pandas.core.frame.dataframe'> rangeindex: 5 entries, 0 4 data columns (total 2 columns): dayofweek    5 non-null object date         5 non-null datetime64[ns] dtypes: datetime64[ns](1), object(1) memory usage: 100.0+ bytes  print(df)    dayofweek       date 0    friday 2015-05-22 1    friday 2012-02-10 2    friday 2014-10-10 3    friday 2011-10-21 4    friday 2011-07-08