Python Pandas : creating a dataframe using a function for one of the fields

Question

我正在尝试创建一个数据框，其中一个字段是使用函数计算的。为此，我使用以下代码:

import pandas as pd

def didSurvive(sex):
    return int(sex == "female")


titanic_df = pd.read_csv("test.csv")
submission = pd.DataFrame({
    "PassengerId": titanic_df["PassengerId"],
    "Survived": didSurvive(titanic_df["Sex"])
})
submission.to_csv('titanic-predictions.csv', index=False)

当我运行此代码时，出现以下错误:

D:\Documents\kaggle\titanic>python predictor.py
File "predictor.py", line 3
def didSurvive() {
^
SyntaxError: invalid syntax
D:\Documents\kaggle\titanic>python predictor.py
D:\Documents\kaggle\titanic>python predictor.py
D:\Documents\kaggle\titanic>python predictor.py
Traceback (most recent call last):
File "predictor.py", line 10, in
"Survived": didSurvive(titanic_df["Sex"])
File "predictor.py", line 4, in didSurvive
return int(sex == "female")
File "C:\Python34\lib\site-packages\pandas\core\series.py", line 92, in wrapper
"{0}".format(str(converter)))
TypeError: cannot convert the series to
D:\Documents\kaggle\titanic>

我认为正在发生的事情是我试图在一系列 bool 值而不是单个 bool 值上运行 int() 。我该如何解决这个问题？

Answer 1

要转换Series的数据类型，您可以使用astype()函数，这应该可以:

def didSurvive(sex):
    return (sex == "female").astype(int)