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Python

intermediate

The Python wrapper is useful for Python developers who wish to seamlessly integrate the what3words Public API into their Python applications, without the hassle of having to manage the low level API calls themselves.

The what3words API is a fast, simple interface which allows you to convert 3 word addresses such as ///index.home.raft to latitude and longitude coordinates such as (-0.203586, 51.521251) and vice versa. It features a powerful autosuggest function, which can validate and autocorrect user input and limit it to certain geographic areas (this powers the search box on our map site). It allows you to request a section of the what3words grid (which can be requested as GeoJSON for easy display on online maps), and to request the list of all languages supported by what3words. For advanced users, autosuggest can be used to post-process voice output. See links on the left to navigate.

All coordinates are latitude,longitude pairs in standard WGS-84 (as commonly used worldwide in GPS systems). All latitudes must be in the range of -90 to 90 (inclusive).

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Installation

The library is available through PyPi. To install what3words, simply:

pip install what3words
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Setup

Import

import what3words
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Initialise

By default, the wrapper will point to the public version of the what3words API. However, if required, the wrapper can be configured to point to a custom endpoint, for example a locally running version of the API. In this case an optional end_point parameter can be passed to the what3words.Geocoder constructor.

Public API:

geocoder = what3words.Geocoder("what3words-api-key")
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API Server:

geocoder = what3words.Geocoder("what3words-api-key", end_point='http://localhost:8080/v3')
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Usage

Convert to 3 word address

This function converts coordinates (expressed as latitude and longitude) to a 3 word address.

More information about convert_To_3wa, including returned results is available in the what3words REST API documentation.

Find the words for (51.484463, -0.195405):

res = geocoder.convert_to_3wa(what3words.Coordinates(51.484463, -0.195405))
print(res)
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Convert to coordinates

This function converts a 3 word address to a position, expressed as coordinates of latitude and longitude.

It takes the words parameter as a string of 3 words 'table.book.chair'

More information about convert_to_coordinates, including returned results is available in the what3words REST API documentation.

Find the coordinates for ///prom.cape.pump:

res = geocoder.convert_to_coordinates('prom.cape.pump')
print(res)
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AutoSuggest

When presented with a 3 words address which may be incorrectly entered, AutoSuggest returns a list of potential correct 3 word addresses. It needs the first two words plus at least the first character of the third word to produce suggestions.

This method provides corrections for mis-typed words (including plural VS singular), and words being in the wrong order.

Optionally, clipping can narrow down the possibilities, and limit results to:

  • One or more countries
  • A geographic area (a circle, box or polygon)

This dramatically improves results, so we recommend that you use clipping if possible.

To improve results even further, set the focus to user’s current location. This will make autosuggest return results which are closer to the user.

More information about autosuggest, including returned results is available in the what3words REST API documentation.

Code example Simple basic call:

res = geocoder.autosuggest('filled.count.soap')
print(res)
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Code example AutoSuggest, clipping the results returned to France and Germany:

res = geocoder.autosuggest('filled.count.soap', clip_to_country="FR,DE")
print(res)
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Code example AutoSuggest, Focus on (51.4243877,-0.34745).

res = geocoder.autosuggest('filled.count.soap', \
    focus=what3words.Coordinates(51.4243877,-0.34745))
print(res)
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Code example AutoSuggest, with Generic Voice input type.

res = geocoder.autosuggest('fun with code', input_type='generic-voice', language='en')
print(res)
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Grid section

Grid section returns a section of the what3words 3m x 3m grid as a set of horizontal and vertical lines covering the requested area, which can then be drawn onto a map.

The requested box must not exceed 4km from corner to corner, or a BadBoundingBoxTooBig error will be returned.

More information about grid_section, including returned results is available in the what3words REST API documentation.

Get a grid for 52.207988,0.116126) in the south west, and 52.208867,0.117540 in the north east:

sw = what3words.Coordinates(52.207988,0.116126)
ne = what3words.Coordinates(52.208867,0.117540)
bb = what3words.BoundingBox(sw, ne)

res = geocoder.grid_section(bb)
print(res)
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Available languages

This function returns the currently supported languages. It will return the two letter code, and the name of the language both in that language and in English.

More information about available_languages, including returned results is available in the what3words REST API documentation.

res = geocoder.available_languages()
print(res)
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Handling errors

Errors returned from the API can be caught with the wrapper through the use of a catch function.

Within the catch function, code and message values which represent the error, are accessible from the error object parameter

autosuggest = geocoder.autosuggest('freshen.overlook.clo', clip_to_country="FR")

if 'error' in autosuggest: # An error has been returned from the API
    code = autosuggest['error']['code']
    message = autosuggest['error']['message']

    print (code, message)
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RegEx Functions

This section introduces RegEx functions that can assist with checking and finding possible what3words addresses in strings. The three main functions covered are:

  • isPossible3wa – Match what3words address format;
  • findPossible3wa – Find what3words address in Text;
  • isValid3wa – Verify a what3words address with the API;

isPossible3wa

Our API wrapper RegEx function “isPossible3wa” can be used used to detect if a text string (like “filled.count.soap“) in the format of a what3words address without having to ask the API. This functionality checks if a given string could be a what3words address. It returns true if it could be, otherwise false.

Note: This function checks the text format but not the validity of a what3words address. Use isValid3wa to verify validity.

import what3words

def main():
    # Initialize the What3Words API with your API key
    api_key = 'YOUR_API_KEY'
    w3w = what3words.Geocoder(api_key)

    # Example what3words addresses
    addresses = ["filled.count.soap", "not a 3wa", "not.3wa address"]

    # Check if the addresses are possible what3words addresses
    for address in addresses:
        is_possible = w3w.isPossible3wa(address)
        print(f"Is '{address}' a possible what3words address? {is_possible}")

if __name__ == "__main__":
    main()
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Expected Output

  • isPossible3wa(“filled.count.soap”) returns true
  • isPossible3wa(“not a 3wa”) returns false
  • isPossible3wa(“not.3wa address”)returns false

findPossible3wa

Our API wrapper RegEx function “findPossible3wa” can be used to detect a what3words address within a block of text, useful for finding a what3words address in fields like Delivery Notes. For example, it can locate a what3words address in a note like “Leave at my front door ///filled.count.soap”. The function will match if there is a what3words address within the text. If no possible addresses are found, it returns an empty list.

Note:

  • This function checks the text format but not the validity of a what3words address. Use isValid3wa to verify validity.
  • This function is designed to work across languages but do not work for Vietnamese (VI) due to spaces within words.
import what3words

def main():
    # Initialize the what3words API with your API key
    api_key = 'YOUR_API_KEY'
    w3w = what3words.Geocoder(api_key)

    # Example texts
    texts = [
        "Please leave by my porch at filled.count.soap",
        "Please leave by my porch at filled.count.soap or deed.tulip.judge",
        "Please leave by my porch at"
    ]

    # Check if the texts contain possible what3words addresses
    for text in texts:
        possible_addresses = w3w.findPossible3wa(text)
        print(f"Possible what3words addresses in '{text}': {possible_addresses}")

if __name__ == "__main__":
    main()
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Expected Output

  • findPossible3wa(“Please leave by my porch at filled.count.soap”) returns ['filled.count.soap']
  • findPossible3wa(“Please leave by my porch at filled.count.soap or deed.tulip.judge”) returns ['filled.count.soap', 'deed.tulip.judge']
  • findPossible3wa(“Please leave by my porch at”) returns []

isValid3wa

Our API wrapper RegEx function “isValid3wa” can be used to determine if a string is a valid what3words address by checking it against the what3words RegEx filter and verifying it with the what3words API.

import what3words

def main():
    # Initialize the what3words API with your API key
    api_key = 'YOUR_API_KEY'
    w3w = what3words.Geocoder(api_key)

    # Example addresses
    addresses = [
        "filled.count.soap",
        "filled.count.",
        "coding.is.cool"
    ]

    # Check if the addresses are valid what3words addresses
    for address in addresses:
        is_valid = w3w.isValid3wa(address)
        print(f"Is '{address}' a valid what3words address? {is_valid}")

if __name__ == "__main__":
    main()
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Expected Outputs

  • isValid3wa(“filled.count.soap”) returns True
  • isValid3wa(“filled.count.”) returns False
  • isValid3wa(“coding.is.cool”) returns False

Also make sure to replace <YOUR_API_KEY> with your actual API key. These functionalities provide different levels of validation for what3words addresses, from simply identifying potential addresses to verifying their existence on Earth.

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