What are all Python Pandas .agg functions?

Question

I am talking about Python Pandas .agg() function, this one:

meanData = all_data.groupby(['Id'])[features].agg('mean')

So, it can do things like:

• Mean
• Median
• Sum
• Max
• Min
• Std

What else can it do? I found nothing on the official documentation page: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.core.groupby.DataFrameGroupBy.agg.html

Answer 1

It can be just about any function that can be applied on a DataFrame object.

print(dir(DataFrame))

When func is a string type, the func name is looked up in the available attributes of the DataFrame object that the .agg method is invoked on.

https://github.com/pandas-dev/pandas/blob/v0.23.4/pandas/core/apply.py#L117

While it gives similar result when doing a division of elements in a DataFrame to write,

df = DataFrame([1,2,3,4])    
df.agg('true_div', 0, 2)

In the real world, you find that the method doing the operation is invoked in a direct manner on the DataFrame

df = DataFrame([1,2,3,4])
df.true_div(2)

Answer 2

You can find the full list in documentation under pandas.core.groupby.GroupBy.some-function-name in the left menu.

List currently includes many aggregation functions:

pipe, all, any, bfill, backfill, count, cumcount, cummax, cummin, cumprod, cumsum, ffill, first, head, last, max, mean, median, min, ngroup, nth, ohlc, pad, prod, rank, pct_change, size, sem, std, sum, var, tail