在pandas数据框中透视表

Question

我有一个要求,我在尝试计算值并将它们放在数据透视表中.

这是我的数据帧,

  Cola        Colb          
 Apple    Rippened 
Orange    Rippened
 Apple  UnRippened
 Mango  UnRippened

我希望输出像这样,

        Rippened  UnRippened
Apple          1           1
Mango          0           1
Orange         1           0

请分享您的想法.

Answer 1

我喜欢这个问题....

选项1

pd.get_dummies(df.Cola).T.dot(pd.get_dummies(df.Colb))

        Rippened  UnRippened
Apple          1           1
Mango          0           1
Orange         1           0

选项2

i, r = pd.factorize(df.Cola.values)
j, c = pd.factorize(df.Colb.values)
n, m = r.size, c.size
b = np.bincount(i * m + j, minlength=n * m).reshape(n, m)

pd.DataFrame(b, r, c)

        Rippened  UnRippened
Apple          1           1
Orange         1           0
Mango          0           1

选项3

df.groupby(['Cola', 'Colb']).size().unstack(fill_value=0)

Colb    Rippened  UnRippened
Cola                        
Apple          1           1
Mango          0           1
Orange         1           0

选项4

df.groupby('Cola').Colb.value_counts().unstack(fill_value=0)

Colb    Rippened  UnRippened
Cola                        
Apple          1           1
Mango          0           1
Orange         1           0

Answer 2

用我最喜欢的: pd.crosstab

df = pd.crosstab(df.Cola, df.Colb)
print(df)

Colb    Rippened  UnRippened
Cola                        
Apple          1           1
Mango          0           1
Orange         1           0

Answer 3

IIUC:

In [178]: d.pivot_table(index='Cola', columns='Colb', aggfunc='size', fill_value=0)
Out[178]:
Colb    Rippened  UnRippened
Cola
Apple          1           1
Mango          0           1
Orange         1           0