pandas.DataFrame.apply

Apply a function along an axis of the DataFrame.

Objects passed to the function are Series objects whose index is either the DataFrame’s index (axis=0) or the DataFrame’s columns (axis=1). By default (result_type=None), the final return type is inferred from the return type of the applied function. Otherwise, it depends on the result_type argument.

param func

function

Function to apply to each column or row.

param axis

{0 or ‘index’, 1 or ‘columns’}, default 0

Axis along which the function is applied:

• 0 or ‘index’: apply function to each column.

• 1 or ‘columns’: apply function to each row.

param broadcast

bool, optional

Only relevant for aggregation functions:

• False or Nonereturns a Series whose length is the

  length of the index or the number of columns (based on the axis parameter)

• Trueresults will be broadcast to the original shape

  of the frame, the original index and columns will be retained.

Deprecated since version 0.23.0.

by result_type=’broadcast’.

param raw

bool, default False

• Falsepasses each row or column as a Series to the

  function.

• Truethe passed function will receive ndarray objects

  instead. If you are just applying a NumPy reduction function this will achieve much better performance.

param reduce

bool or None, default None

Try to apply reduction procedures. If the DataFrame is empty, apply will use reduce to determine whether the result should be a Series or a DataFrame. If reduce=None (the default), apply’s return value will be guessed by calling func on an empty Series (note: while guessing, exceptions raised by func will be ignored). If reduce=True a Series will always be returned, and if reduce=False a DataFrame will always be returned.

Deprecated since version 0.23.0.

by result_type='reduce'.

param result_type

{‘expand’, ‘reduce’, ‘broadcast’, None}, default None

These only act when axis=1 (columns):

• ‘expand’ : list-like results will be turned into columns.

• ‘reduce’returns a Series if possible rather than expanding

  list-like results. This is the opposite of ‘expand’.

• ‘broadcast’results will be broadcast to the original shape

  of the DataFrame, the original index and columns will be retained.

The default behaviour (None) depends on the return value of the applied function: list-like results will be returned as a Series of those. However if the apply function returns a Series these are expanded to columns.

New in version 0.23.0.

param args

tuple

Positional arguments to pass to func in addition to the array/series. **kwds Additional keyword arguments to pass as keywords arguments to func.

return

Series or DataFrame Result of applying func along the given axis of the DataFrame.

Warning

This feature is currently unsupported by Intel Scalable Dataframe Compiler