您好我有以下数据框。
Group Size
Short Small
Short Small
Moderate Medium
Moderate Small
Tall Large
我想计算同一行在数据帧中显示的时间的频率。
Group Size Time
Short Small 2
Moderate Medium 1
Moderate Small 1
Tall Large 1
答案 0 :(得分:75)
您可以使用groupby的size
:
In [11]: df.groupby(["Group", "Size"]).size()
Out[11]:
Group Size
Moderate Medium 1
Small 1
Short Small 2
Tall Large 1
dtype: int64
In [12]: df.groupby(["Group", "Size"]).size().reset_index(name="Time")
Out[12]:
Group Size Time
0 Moderate Medium 1
1 Moderate Small 1
2 Short Small 2
3 Tall Large 1
答案 1 :(得分:28)
您还可以尝试pd.crosstab()
Group Size
Short Small
Short Small
Moderate Medium
Moderate Small
Tall Large
pd.crosstab(df.Group,df.Size)
Size Large Medium Small
Group
Moderate 0 1 1
Short 0 0 2
Tall 1 0 0
编辑:为了让你出局
pd.crosstab(df.Group,df.Size).replace(0,np.nan).\
stack().reset_index().rename(columns={0:'Time'})
Out[591]:
Group Size Time
0 Moderate Medium 1.0
1 Moderate Small 1.0
2 Short Small 2.0
3 Tall Large 1.0
答案 2 :(得分:0)
其他可能性正在使用.pivot_table()
和aggfunc='size'
df_solution = df.pivot_table(index=['Group','Size'], aggfunc='size')