Extract date components from Date column in pandas dataframe

datecolumn_to_datepart.py

# Extracting date components from a Date column in Pandas using IPython
# Converting to DatetimeIndex is 100x faster than using DataFrame.apply() 

import pandas as pd
dates = pd.DataFrame({"Date": pd.date_range(start="1970-01-01", end="2037-12-31")})

print(dates.head())
#         Date
# 0 1970-01-01
# 1 1970-01-02
# 2 1970-01-03
# 3 1970-01-04
# 4 1970-01-05

print(dates.shape)
# (24837, 1)

print(dates.dtypes)
# Date    datetime64[ns]
# dtype: object

%timeit -n10 -r10 dates.Date.apply(lambda x: x.year)
# 10 loops, best of 10: 111 ms per loop

%timeit -n10 -r10 pd.DatetimeIndex(dates.Date).year
# 10 loops, best of 10: 1.01 ms per loop

%timeit -n10 -r10 dates.Date.dt.year
# 10 loops, best of 10: 3.55 ms per loop