Trim whitespace in Python (pandas)

When to use it

Keys, codes and categories padded with spaces, tabs or line breaks, before any comparison or lookup.

How

Series.str.strip(chars) with the exact characters. Without an argument it removes every Unicode whitespace character.

df["customer_code"].str.strip(" \t\r\n")

• Missing values stay <NA>.
• Use .mask(s == "") afterwards to turn empty strings into missing.

Pitfalls

• Relying on the tool's default definition of whitespace.
• Casting identifiers to numbers to drop padding.
• Trimming only one side.