从dataframe列中的字典中提取值

Question

我有一个带有字典的列的数据框。 我需要从字典中提取一个值

df = pd.DataFrame (x.edges (data=True), columns = ['emp1','emp2','weight'])

       emp1     emp2         weight

0      Joan      Lee  {'weight': 3}

1      Joan     Andy  {'weight': 1}

2   Vincent    Frida  {'weight': 2}

我试图从权重列中获取值

df['newweight'] = df.weight.apply (lambda x: x.get ('value'))

       emp1     emp2         weight newweight

0      Joan      Lee  {'weight': 3}      None

1      Joan     Andy  {'weight': 1}      None

2   Vincent    Frida  {'weight': 2}      None

我做错了什么

Answer 1

x.get ('value')将查找名为'value'的键，但您的字典只有一个名为'weight'的键

^{} is specifically designed to return ^{} when you attempt to ^{} the value of a nonexistent key，这正是这里发生的事情

Answer 2

我明白了

df['newweight'] = df.weight.apply(lambda x: x['weight'])