我有一个具有某些特征的类别（身高和体重，由np.where定义），而另一个具有其他特征的类别（如果某人是双胞胎，有多少同胞，由np.where定义）。我想看看有多少人同时属于这两个类别（例如如果制作了维恩图，那么会有多少人处于中心？）。
我正在导入CSV文件的列。
该表如下所示：
Child Inches Weight Twin Siblings
0 A 53 100 Y 3
1 B 54 110 N 4
2 C 56 120 Y 2
3 D 58 165 Y 1
4 E 60 150 N 1
5 F 62 160 N 1
6 H 65 165 N 3
import pandas as pd
import numpy as np
file = pd.read_csv(r'~/Downloads/Test3 CVS_Sheet1.csv')
#%%
height = file["Inches"]
weight = file["Weight"]
twin = file["Twin"]
siblings = file["Siblings"]
#%%
area1 = np.where((height <= 60) & (weight <= 150))[0]
#%%
#has two or more siblings (and is a twin)
group_a = np.where((siblings >= 2) & (twin == 'Y'))[0]
#has two or more siblings (and is not a twin)
group_b = np.where((siblings >= 2) & (twin == 'N'))[0]
#has only one sibling (and is twin)
group_c = np.where((siblings == 1) & (twin == 'Y'))[0]
#has only one sibling (and is not a twin)
group_d = np.where((siblings == 1) & (twin == 'N'))[0]
#%%
for i in area1:
if group_a==True:
print("in area1 there are", len(i), "children in group_a")
elif group_b==True:
print("in area1 there are", len(i), "children in group_b")
elif group_c==True:
print("in area1 there are", len(i), "children in group_c")
elif group_d==True:
print("in area1 there are", len(i), "children in group_d")
我收到错误消息：“ ValueError：具有多个元素的数组的真值不明确。请使用a.any（）或a.all（）”
我希望输出如下：
"in area1 there are 2 children in group_a"
"in area1 there are 1 children in group_b"
"in area1 there are 0 children in group_c"
"in area1 there are 1 children in group_d"
提前致谢！
最佳答案
在您的示例中，我将采用稍微不同的设计。你可以这样做：
df['area1'] = np.where((df.Inches <= 60) & (df.Weight <= 150),1,0)
df['group_a'] = np.where((df.Siblings >= 2) & (df.Twin == 'Y'),1,0)
df['group_b'] = np.where((df.Siblings >= 2) & (df.Twin == 'N'),1,0)
df['group_c'] = np.where((df.Siblings == 1) & (df.Twin == 'Y'),1,0)
df['group_d'] = np.where((df.Siblings == 1) & (df.Twin == 'N'),1,0)
结果将如下所示：
从这一点开始，您可以构建查询，以便查看group_b：
df.groupby(['area1'])['group_b'].sum()[1]
您将获得所需的结果：1.您可以使用总和或计数来调整表格。
最后：
for col in df.columns[6:]:
r = df.groupby(['area1'])[col].sum()[1]
print ("in area1 there are",r,'children in',col)
将产生：
in area1 there are 2 children in group_a
in area1 there are 1 children in group_b
in area1 there are 0 children in group_c
in area1 there are 1 children in group_d
关于python - 想知道两个不同子集的重叠中有多少个对象，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/57065716/