Question

我正在尝试分析Nba球员数据集以进行作业。我有一个包含名称，得分，助攻，年等的数据集。我试图分析2017年出战的球员，所以首先我要打印他们的姓名，得分，助攻等。

当我尝试以下代码时：

for i in df1.columns:
    if df1['Year'] == 2017:
         print(df1.loc[:, ["Year","Player","Pos","Team","Games","AST","PTS","PPG"]])

此代码出现错误，告诉我需要添加.any()或.all()。

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-101-c1ff6e025cb7> in <module>()
      1 for i in df1.columns:
----> 2     if df1['Year'] == 2017:
      3          print(df1.loc[:, ["Year","Player","Pos","Team","Games","AST","PTS","PPG"]])

/opt/conda/lib/python3.6/site-packages/pandas/core/generic.py in __nonzero__(self)
   1574         raise ValueError("The truth value of a {0} is ambiguous. "
   1575                          "Use a.empty, a.bool(), a.item(), a.any() or a.all()."
-> 1576                          .format(self.__class__.__name__))
   1577 
   1578     __bool__ = __nonzero__

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

我将它们添加到了代码中。

for i in df1.columns:
if df1['Year'].all() == 2017:
     print(df1.loc[:, ["Year","Player","Pos","Team","Games","AST","PTS","PPG"]])

此代码块不返回任何输出（无错误等）

我还认为可以通过列表理解来做到这一点，但我找不到办法。应该是这样的：

df2 = [df1['Year','Player','Pos','Team','Games','AST','PTS','PPG'] if (df1['Year'].any() == 2017) else "Bye" for i in df1.Year]
    print(df2)

但是这里有一个问题，就是这段代码总是输入else语句，并且只显示“ Bye”。

Answer 1

如果您只想打印年份为2017的其他列，则可以这样做

print(df1[df1['Year']==2017].loc[:,["Year","Player","Pos","Team","Games","AST","PTS","PPG"]])

无需像您那样遍历列或使用if语句，pandas数据框就具有良好的索引

数据框列是否满足条件

1 个答案: