ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.

Posted 2022-04-19 Data+Science+Insight

 ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

目录

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

问题：

解决：

完整错误：

---

问题：

如果不使用圆括号（）对条件进行分组，python将根据运算符优先级计算表达式，这可能会给出运算符&和~的意外结果。

因为缺少圆括号，如下语句：

df['Shares']>=100 & df['Shares']<=150

被系统解读为：

df['Shares'] >= (100 & df['Shares']) <= 150

import pandas as pd

data = 
    'Name': ['Microsoft Corporation', 'Google, LLC', 'Tesla, Inc.',\\
             'Apple Inc.', 'Netflix, Inc.'],
    'Symbol': ['MSFT', 'GOOG', 'TSLA', 'AAPL', 'NFLX'],
    'Industry': ['Tech', 'Tech', 'Automotive', 'Tech', 'Entertainment'],
    'Shares': [100, 50, 150, 200, 80]


df = pd.DataFrame(data)
# print(df)
df


df_filtered = df[df['Shares']>=100 & df['Shares']<=150]
print(df_filtered)

解决：

为条件关系添加括号；

df_filtered = df[(df['Shares']>=100) & (df['Shares']<=150)]
df_filtered
# print(df_filtered)

 

完整错误：

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-16-545c272b68ba> in <module>
----> 1 df_filtered = df[df['Shares']>=100 & df['Shares']<=150]
      2 print(df_filtered)

D:\\anaconda\\lib\\site-packages\\pandas\\core\\generic.py in __nonzero__(self)
   1441     def __nonzero__(self):
   1442         raise ValueError(
-> 1443             f"The truth value of a type(self).__name__ is ambiguous. "
   1444             "Use a.empty, a.bool(), a.item(), a.any() or a.all()."
   1445         )

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

参考：pandas

参考：ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().