replace alphanumeric values in a column dataframe-CodePudding

I have a big data frame that looks like this:

a, b, c
4f5t-4656, x, y
3jsu-56hj, x, y
gfhdu670-9, x, y
fgfj-6fhf, x, y
ELE, x, y
ELE, x, y

My goal is to replace all the alphanumeric values in column a by the the letters 'LCD'. I have tried:

df['a']=df['a'].replace([a-z0-9-], 'LCD', regex=True)

but I am getting the "SyntaxError: invalid syntax"

What's the problem with the code? can anyone help?

CodePudding user response：

My bet is that you don't want to replace each matching character by LCD, but the whole series of characters, thus you probably want to add a quantifier in your regex (in addition to the missing quotes that give you the SyntaxError):

df['a'] = df['a'].replace('[a-z0-9-] ', 'LCD', regex=True)

Output:

     a  b  c
0  LCD  x  y
1  LCD  x  y
2  LCD  x  y
3  LCD  x  y
4  ELE  x  y
5  ELE  x  y

CodePudding user response：

You simply need to wrap this expression in quotes

df['a'].replace(r'[a-z0-9-]', 'LCD', regex=True)

I think that should work