UK-postcode-lib

Simple UK post-code validation and formatting.

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This library includes the post-codes from the Code-Point Open data, november 2017.

To update the data, you must download the archive from OS Code-Point Open, or Doogal GB, extract it the folder CSV and run the import_csv.py script.

Motivation: Regex validation is hard to maintain and only goes so far. There are no libraries for checking that the post-code is postally valid.

Note: This library is just as good as the database included in it. If some post-codes are missing, or are deprecated, it's because I'm using free data.

Usage

As a command line app

Format and validate a post-code:

$ python3.6 postcode "M1 1AE"

As a python library

postcode.format_code(code: str, join: bool=True)

This function returns a string, or a tuple, depending if the join param is True.

Example:

import postcode

postcode.format_code('M11ae')
# M1 1AE
postcode.format_code('w1k 7aa')
# W1K 7AA
postcode.format_code('ab11aa', join=False)
# ('AB1', '1AA')

postcode.naive_validation(code: str) -> bool

This function validates a code, using a REGEX. The code is not guaranteed to be postally valid.

Example:

postcode.naive_validation('M1 1AE')
# True
postcode.naive_validation('ab11aa')
# True
postcode.naive_validation('A 1AA') # No digit in 1st group
# False

postcode.validate_code(code: str) -> bool

This function validates a code, using the database. Before calling it, you must call the load_database() function.

Example:

postcode.load_database()

postcode.validate_code('M1 1AE')
# True
postcode.validate_code('AB11AA')
# False

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Free database downloads:

• OS Code-Point Open post-codes (updated quarterly: February, May, August and November)
• Doogal GB Postcodes (older data)

Resources:

• Stackoverflow 1: https://stackoverflow.com/questions/164979/uk-postcode-regex-comprehensive
• Stackoverflow 2: https://stackoverflow.com/questions/13969461/javascript-uk-postcode-validation
• Online tester: Royal Mail Postcode Finder

Similar tools:

• UK postcode utils on PyPi
• Parsing a UK postcode on Activestate
• UK Postcode Validation, JavaScript and PHP