python pandas replacing strings in dataframe with numbers

Question

Is there anyway to use the mapping function or something better to replace values in an entire dataframe?

I only know how to perform the mapping on series.

I

Answer 1

You can build dictionary from column values itself and fill like below

x=df['Item_Type'].value_counts()
item_type_mapping={}
item_list=x.index
for i in range(0,len(item_list)):
    item_type_mapping[item_list[i]]=i

df['Item_Type']=df['Item_Type'].map(lambda x:item_type_mapping[x])