List with attributes of persons loaded into pandas dataframe df2. For cleanup I want to replace value zero (0 or '0') by np.nan.

df2.dtypes

ID                   object
Name                 object
Weight              float64
Height              float64
BootSize             object
SuitSize             object
Type                 object
dtype: object

Working code to set value zero to np.nan:

df2.loc[df2['Weight'] == 0,'Weight'] = np.nan
df2.loc[df2['Height'] == 0,'Height'] = np.nan
df2.loc[df2['BootSize'] == '0','BootSize'] = np.nan
df2.loc[df2['SuitSize'] == '0','SuitSize'] = np.nan

Believe this can be done in a similar/shorter way:

df2[["Weight","Height","BootSize","SuitSize"]].astype(str).replace('0',np.nan)

However the above does not work. The zero’s remain in df2. How to tackle this?

I think you need replace by dict:

cols = ["Weight","Height","BootSize","SuitSize","Type"]
df2[cols] = df2[cols].replace({'0':np.nan, 0:np.nan})

You could use the ‘replace’ method and pass the values that you want to replace in a list as the first parameter along with the desired one as the second parameter:

cols = ["Weight","Height","BootSize","SuitSize","Type"]
df2[cols] = df2[cols].replace(['0', 0], np.nan)

data['amount']=data['amount'].replace(0, np.nan)
data['duration']=data['duration'].replace(0, np.nan)

Try:

df2.replace(to_replace={
             'Weight':{0:np.nan}, 
             'Height':{0:np.nan},
             'BootSize':{'0':np.nan},
             'SuitSize':{'0':np.nan},
                 })

in column “age”, replace zero with blanks

df['age'].replace(['0', 0'], '', inplace=True)

Replace zero with nan for single column

df['age'] = df['age'].replace(0, np.nan)

Replace zero with nan for multiple columns

cols = ["Glucose", "BloodPressure", "SkinThickness", "Insulin", "BMI"]

df[cols] = df[cols].replace(['0', 0], np.nan)

Replace zero with nan for dataframe

df.replace(0, np.nan, inplace=True)

Another alternative way:

cols = ["Weight","Height","BootSize","SuitSize","Type"]
df2[cols] = df2[cols].mask(df2[cols].eq(0) | df2[cols].eq('0'))

If you just want to o replace the zeros in whole dataframe, you can directly replace them without specifying any columns:

df = df.replace({0:pd.NA})