python - 更改具有条件的数据框列

Question

样本数据框

CountryName

India|Pakistan
Pakistan|Agansitan
Sweden
Nepal|Bhutan

输出带有新列的数据框

CountryName           MainCountry

India|Pakistan        India
Pakistan|Agansitan    Pakistan
Sweden                Sweden
Nepal|Bhutan          Nepal

我试过了

df["MainCountry"] =df['CountryName'].str.contains("[|].*","")

它给出的是真的还是假的，你能帮我找出如何得到它吗？

标签： pythonpython-3.xpandas

Answer 1

你可以

In [87]: df['MainCountry'] = df['CountryName'].str.split('|').str[0]

In [88]: df
Out[88]:
          CountryName MainCountry
0      India|Pakistan       India
1  Pakistan|Agansitan    Pakistan
2              Sweden      Sweden
3        Nepal|Bhutan       Nepal