How can I remove all non-numeric characters from all the values in a particular column in pandas dataframe?

Question

I have a dataframe which looks like this:

     A       B           C
1   red78   square    big235
2   green   circle    small123
3   blue45  triangle  big657         


        

Answer 1

Use str.extract and pass a regex pattern to extract just the numeric parts:

In[40]:
dfObject['C'] = dfObject['C'].str.extract('(\d+)', expand=False)
dfObject

Out[40]: 
        A         B    C
1   red78    square  235
2   green    circle  123
3  blue45  triangle  657

If needed you can cast to int:

dfObject['C'] = dfObject['C'].astype(int)