simple pivot table of pandas dataframe

Question

I\'m trying to do a seemingly very simple task. Given a dataframe:

daf = pd.DataFrame({\'co\':[\'g\',\'r\',\'b\',\'r\',\'g\',\'r\',\'b\',\'g\'], \'sh\':[

Answer 1

It can be done more simply using pandas.crosstab:

>>> pandas.crosstab(d.co, d.sh)
sh  c  r  s
co         
b   1  1  0
g   1  2  0
r   0  1  2

You can do it with pivot_table, but it will give you NaN instead of 0 for missing combos. You need to specify len as the aggregating function:

>>> d.pivot_table(index='co', columns='sh', aggfunc=len)
sh   c  r   s
co           
b    1  1 NaN
g    1  2 NaN
r  NaN  1   2