Applying a geohash_decode function to a column in a dataframe

Question

Well, I geohash_encoded the geographical coordinates to geohashes. My aim is to calculate the distance with some level of accuracy. I am trying to geohash_decode the geohashes back to geographical coordinates but I have failed to come up with a function that can do that to a column in a dataframe

Answer 1

Assuming:

• you are asking about Python (apologies if this was an R, Scala or other dataframe question, but you didn't specify )
• you have a Python pandas DataFrame object df
• df has a column named geohash containing your geohashes
• you have the geohash2 library installed and imported (this may work with other Geohash libraries...)
• you want to overwrite df with a new DataFrame containing all the old data plus the new latitude and longitude columns

The following should work:

def gh_decode(hash):
    lat, lon = geohash2.decode(hash)
    return pd.Series({"latitude":lat, "longitude":lon})

df = df.join(df["geohash"].apply(gh_decode))