Combine two columns of text in pandas dataframe

Question

I have a 20 x 4000 dataframe in Python using pandas. Two of these columns are named Year and quarter. I\'d like to create a variable called p

Answer 1

Use of a lamba function this time with string.format().

import pandas as pd
df = pd.DataFrame({'Year': ['2014', '2015'], 'Quarter': ['q1', 'q2']})
print df
df['YearQuarter'] = df[['Year','Quarter']].apply(lambda x : '{}{}'.format(x[0],x[1]), axis=1)
print df

  Quarter  Year
0      q1  2014
1      q2  2015
  Quarter  Year YearQuarter
0      q1  2014      2014q1
1      q2  2015      2015q2

This allows you to work with non-strings and reformat values as needed.

import pandas as pd
df = pd.DataFrame({'Year': ['2014', '2015'], 'Quarter': [1, 2]})
print df.dtypes
print df

df['YearQuarter'] = df[['Year','Quarter']].apply(lambda x : '{}q{}'.format(x[0],x[1]), axis=1)
print df

Quarter     int64
Year       object
dtype: object
   Quarter  Year
0        1  2014
1        2  2015
   Quarter  Year YearQuarter
0        1  2014      2014q1
1        2  2015      2015q2