format_postcode: Format a postcode

In Health-SocialCare-Scotland/phsmethods: Standard Methods for Use in Public Health Scotland

Format a postcode

Description

format_postcode takes a character string or vector of character strings. It extracts the input values which adhere to the standard UK postcode format (with or without spaces), assigns the appropriate amount of spacing to them (for both pc7 and pc8 formats) and ensures all letters are capitalised.

Usage

format_postcode(x, format = c("pc7", "pc8"), quiet = FALSE)

Arguments

x	A character string or vector of character strings. Input values which adhere to the standard UK postcode format may be upper or lower case and will be formatted regardless of existing spacing. Any input values which do not adhere to the standard UK postcode format will generate an NA and a warning message - see Value section for more information.
format	A character string denoting the desired output format. Valid options are pc7 and pc8. The default is pc7. See Value section for more information on the string length of output values.
quiet	(optional) If quiet is TRUE all messages and warnings will be suppressed. This is useful in a production context and when you are sure of the data or you are specifically using this function to remove invalid postcodes. This will also make the function a bit quicker as fewer checks are performed.

Details

The standard UK postcode format (without spaces) is:

• 1 or 2 letters, followed by

• 1 number, followed by

• 1 optional letter or number, followed by

• 1 number, followed by

• 2 letters

UK government regulations mandate which letters and numbers can be used in specific sections of a postcode. However, these regulations are liable to change over time. For this reason, format_postcode does not validate whether a given postcode actually exists, or whether specific numbers and letters are being used in the appropriate places. It only assesses whether the given input is consistent with the above format and, if so, assigns the appropriate amount of spacing and capitalises any lower case letters.

Value

When format is set equal to pc7, format_postcode returns a character string of length 7. 5 character postcodes have two spaces after the 2nd character; 6 character postcodes have 1 space after the 3rd character; and 7 character postcodes have no spaces.

When format is set equal to pc8, format_postcode returns a character string with maximum length 8. All postcodes, whether 5, 6 or 7 characters, have one space before the last 3 characters.

Any input values which do not adhere to the standard UK postcode format will generate an NA output value and a warning message. A warning is generated rather than an error so as not to let one erroneously recorded postcode in a large input vector prevent the remaining entries from being appropriately formatted.

Any input values which do adhere to the standard UK postcode format but contain lower case letters will generate a warning message explaining that these letters will be capitalised.

Examples

format_postcode("G26QE")
format_postcode(c("KA89NB", "PA152TY"), format = "pc8")

library(dplyr)
df <- tibble(postcode = c("G429BA", "G207AL", "DD37JY", "DG98BS"))
df %>%
  mutate(postcode = format_postcode(postcode))

Health-SocialCare-Scotland/phsmethods documentation built on Jan. 28, 2024, 3:18 a.m.