Regular Expression - regex - Python

a sequence of characters used to check whether a pattern exists in a given text (string) or not help manipulte textual data

• Regex Applications - Examples:
  • search engines
  • search and replace tools of word processors and text editors
  • Validation of email addresses or passwords

re library - Functions

• compile()
• search() –> scans the string and looking for the text location
• group() –> returns the string matched
• findall()
• sub()
• split()
• match()

  returns a match object if the text matches the pattern. Otherwise, it returns None

Repetitions

{x} –> x times. {x,} –> x times, at least {x, y} –> between x and y times

## Code Examples

• re.search(r’Co.k.e’, ‘Cookie’).group() ‘Cookie’

Notes

• [abc] - Matches a or b or c.
• [a-zA-Z0-9] - Matches any letter from (a to z) or (A to Z) or (0 to 9).

shutil

• A python library that is used for high level file opertations, such as:

  • Copying Files
  • Copying File Metadata
  • Working With Directory Trees
  • Finding Files
  • Archives
  • File System Space