CODEWITHSUNDEEP
pythonpandasdataframe
Danny David Leybzon
Danny David Leybzon

Reputation: 680

How do I group lat-lon pairings in a Pandas DataFrame?

I have a dataframe that looks like:

lon        lat
-77.487    39.044
-77.487    39.044
-122.031   37.354
-77.487    39.044

I want to group these lon-lat pairings with a resulting count, like so:

lon        lat      count
-77.487    39.044   3
-122.031   37.354   1

How can I do this? The group() function only appears to allow for grouping by one column.

Upvotes: 3

Views: 1581

Answers (2)

Shijo
Shijo

Reputation: 9711

Please find the documentation from the following link

http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.groupby.html

df_data=df_data.groupby(['lon','lat']).size()
print df_data

Upvotes: 1

Nickil Maveli
Nickil Maveli

Reputation: 29711

You could use groupby.size and rename the column created followed by reset_index to get back the desired dataframe.

print(df.groupby(['lon', 'lat']).size().rename('count').reset_index())

       lon     lat  count
0 -122.031  37.354      1
1  -77.487  39.044      3

Upvotes: 6

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