I'm importing a excel file into python with pd.read_excel() The columns names in the file like this :

columns_name_xlsx = ['Date:', 'Heure:','P1 (W)', 'P2 (W)', 'P3 (W)']

I would like to get :

columns_name_expected = ['date:', 'heure:','p1_(w)', 'p2_(w)', 'p3_(w)']

I tried with :

df.rename(str.lower.replace(' ', '_'), axis='columns')

But it does not work. Does sb have an idea ?

Thanks !

CodePudding user response：

df.columns = (x.lower().replace(' ', '_') for x in df.columns)

CodePudding user response：

Your solution does not work because

1. You are trying to chain two methods which is not really possible
2. The replace methods requires to provide arguments (' ' and _)

Assuming this DataFrame exists

# Build mock dataframe
df = pd.DataFrame(columns=['Date:', 'Heure:', 'P1 (W)', 'P2 (W)', 'P3 (W)'])

The simplest method is to iteratively apply a transformation on the initial column name as such

df1 = df.rename(columns={v: v.lower().replace(' ', '_') for v in df.columns})

Alternatively, you could chain operations and build a custom function

df1 = df.rename(str.lower, axis=1).rename(lambda x: x.replace(' ', '_'), axis=1)

I hope that helps!