Converting States to Zip Codes

How to Convert States to Zip Codes Using Python Programming

In this tutorial, we’ll be exploring how to convert US states to ZIP codes using Python programming. This can be extremely useful for tasks such as creating mailing labels, analyzing customer data, or running marketing campaigns.

Step 1: Gathering Data

Before we begin, we need to gather a database of every ZIP code in the United States and which state it belongs to. One free resource for this data is the US Census Bureau, which offers a downloadable spreadsheet containing this information.

Downloading the US Census Bureau ZIP Code Data

To access the US Census Bureau ZIP code data, visit their website at and download the most recent version of the “Cartographic Boundary Shapefiles – ZIP Code Tabulation Areas (ZCTAs)”.

After unzipping the downloaded file, you’ll find several folders. The one we’re interested in is the “shp” folder, which contains the shapefiles that we’ll be working with.

Step 2: Importing Libraries

To work with shapefiles in Python, we need to import the necessary libraries. The most common ones are geopandas and shapely. You can install them using pip:

pip install geopandas shapely

Step 3: Reading the Shapefile

Now that we have our libraries, we need to read the shapefile into our Python script. We can do this with geopandas’ read_file() function, passing in the path to the “shp” folder:

import geopandas as gpd

shapefile = gpd.read_file("/path/to/shp/folder")

Step 4: Cleaning the Data

The shapefile contains a lot of unnecessary data that we don’t need. We can filter the data by only selecting the columns we need and dropping any rows that don’t have a ZIP code. We also need to make sure all of the ZIP codes are strings:

# Selecting columns
data = shapefile[["ZCTA5CE10", "STATEFP10"]]

# Dropping rows without a ZIP code
data = data.dropna(subset=["ZCTA5CE10"])

# Converting ZIP codes to strings
data["ZCTA5CE10"] = data["ZCTA5CE10"].astype(str)

Step 5: Converting States to ZIP Codes

Finally, we can convert states to ZIP codes by selecting only the rows that match a certain state and concatenating the ZIP codes into a single string. Here’s an example function that does just that:

def state_to_zip(state):
    # Selecting rows that match the state
    state_data = data[data["STATEFP10"] == state]

    # Concatenating ZIP codes into a single string
    zip_codes = ", ".join(state_data["ZCTA5CE10"].tolist())

    return zip_codes


By following these simple steps, we can easily convert US states to ZIP codes using Python programming. This can be extremely useful for a wide range of tasks and is a great tool to have in your programming arsenal.

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