from worldfinder._internals import load_data
[docs]
def get_countries(city):
"""
Return all unique countries that contain a given city.
Parameters
----------
city : str
The name of the city to search for.
Returns
-------
list of str
A list of unique countries (in their original case) that contain the
specified city. The list will be deduplicated.
Examples
--------
>>> get_countries("London")
["Canada", "United Kingdom", "United States"]
"""
# Check input is a string
if not isinstance(city, str):
raise TypeError(f"City should be a string, instead got '{type(city)}'")
# Ensure 'city' is not empty
if city.strip() == '':
raise ValueError("City cannot be an empty string")
# Load city data from CSV (replace with correct path/filename as needed)
city_df = load_data("src/worldfinder/data", "cities.csv")
# Check if the city exists in the dataset (case-insensitive)
city_mask = city_df["name"].str.lower().eq(city.strip().lower())
if not city_mask.any():
raise ValueError(
"City is not in the database. Please ensure correct spelling or try alternative names"
)
# Filter rows that match the given city (case-insensitive)
matched_rows = city_df[city_mask]
# Extract unique countries in their original case
unique_countries = matched_rows["country_name"].unique().tolist()
# Return the list of unique countries
return unique_countries