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Filtering phone numbers

Now, you need to write a script for a cell-phone searcher. It should scan a list of phone numbers and return those that meet certain characteristics.

The phone numbers in the list have the structure:

  • Optional area code: 3 numbers
  • Prefix: 4 numbers
  • Line number: 6 numbers
  • Optional extension: 2 numbers

E.g. 654-8764-439434-01.

You decide to use .findall() and the non-capturing group's negative lookahead (?!) and negative lookbehind (?<!).

The list cellphones, containing three phone numbers, and the re module are loaded in your session. You can use print() to view the data in the IPython Shell.

This exercise is part of the course

Regular Expressions in Python

View Course

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

for phone in cellphones:
	# Get all phone numbers not preceded by area code
	number = re.____(r"(____-)____-____-____", ____)
	print(number)
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