R: Data Quality Check: Zip Code matching the City

Question

Can someone help me to realize an idea in R?

I want to achieve, that when R gets an Input File with e.g. a list of companies and their address, it will check wether the zip Code fits to the City for each Company. I have a list of all cities and Zip codes from a certain Country. How can I implement the list into an if sentence?

Did someone Programm something similar before?

Thanks for ur help! Sandra

Answer 1

Just a quick example of what one could do. It is, however, probably better to use fuzzy matching for your cities.

# City codes (all city codes can be found at https://www.allareacodes.com/)
my_city_codes <- data.frame(code = c(201:206), 
                            cities = c("Jersey City, NJ", "District of Columbia", "Bridgeport, CT", "Manitoba", "Birmingham, AL", "Seattle, WA"),
                            stringsAsFactors = FALSE)

# Function for checking if city/city-code matches those in the registries
adress_checker <- function(adress, citycodes) {
  # Finding real city
  real_city <- my_city_codes$cities[which(adress$code == my_city_codes$code)]

  # Checking if cities are the same
  if(real_city == adress$city) {
    return("Correct city")
  } else {
    return("Incorrect city")
  }
}

# Adresses to check
right_city <- data.frame(code = 205, city = c("Birmingham, AL"), stringsAsFactors = FALSE)
wrong_city <- data.frame(code = 205, city = c("Las Vegas"), stringsAsFactors = FALSE)

# Testing function
adress_checker(right_city, my_city_codes)
[1] "Correct city"
adress_checker(wrong_city, my_city_codes)
[1] "Incorrect city"