从 dataframe 列中的字典中提取值

Question

I have a DataFrame with a column with dictionaries. I need to extract a value from the dictionary.

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}

I try to get just the value from the weight column

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

What am I doing incorrectly?

Answer 1

x.get ('value') would look for the key called 'value' , but your dictionary has only one key called 'weight' .

dict.get is specifically designed to return None when you attempt to get the value of a nonexistent key , which is exactly what's happening here.

Answer 2

figured it out.

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