Pandas error KeyError: 'gender'

[jairajsahgal]

Apparently in lines
#Step by step approad, the one-liners can be found below their respective tables
df=df[df["gender"]=="M"]
df=df[["name","count"]]
df=df.groupby("name")
df=df.sum()
df=df.sort_values("count",ascending=False)
df.head(10)
Error is coming after running it second time.
Also, the one-liner is also not running.
This is the first time I have raised issue in Github