dataframe的字符类型dtypes为什么是object,而不是str？

Question

import pandas as pd
a=[1,2,3,1]
b=["a","b","c","d"]
df=pd.DataFrame({"A":a,"B":b})
print(df.dtypes)

1. int64
2. object

dtype: object
B列的dtypes为什么不是str，而是object?

Answer 1

因为字符串长度是不固定的，pandas没有用字节字符串的形式而是用了object ndarray
https://stackoverflow.com/que...