Python Day 54 – intro to regex

Went through some tutorials for regex today…

I learned:

• \d can be used to replace any digit from 0 to 9
• . is a wildcard
  • To use normal period. use \.
• To specify characters use []
  • ex: [abc]an
    • To match any value that starts with a or b or c, and ends in ‘an’
  • To exclude, use [^abc]
  • Or use range [a-c]
• To repetitions of characters
  • A{1,6} to signify how many repetitions
  • A+ one or more repetitions
  • A* zero or more repetitions
• Optional characters
  • ?
• White space characters
  • \s
  • \S (any non white space characters)
• Starting and ending
  • ^…$
  • To cap off start and end values which helps prevent false positives (eg: unSUCCESSFUL)
• Capturing a group
  • Use ()…
  • Can be useful for separating files from extension:
    • ^(file_name.+)\.png$

I’m still confused on:

For this dataset I’m practicing on I’m being asked to replace a letter in a string, however using the .str.replace(r”,”) function doesn’t seem to be working. I’ll continue this one tomorrow.