Having issue summarising python dataframe to one line per record

Question

I've got a dataframe in the form:

df = pd.DataFrame({'id':['a', 'a', 'a', 'b','b'],'var':[1,2,3,5,9]})

and I'm trying to reshape it so that there is one line per 'id' and the values 'var' are displayed across in one line, so 'a' would have 1,2,3 ... 'b' would have '5,9'

I've tried with:

test = pd.crosstab(df.id, df.var)  # but it does not work?

If someone could help me it would be much appreciated

EDIT, I enclose the desired results as a picture here

Answer 1

You must supply the correct arguments, like:

pd.crosstab(index=df['id'], columns=df['var'])

var  1  2  3  5  9
id                
a    1  1  1  0  0
b    0  0  0  1  1