Pandas DataFrame - transform() function

DataFrame - transform() function

The transform() function is used to call function (func) on self producing a DataFrame with transformed values and that has the same axis length as self.


DataFrame.transform(self, func, axis=0, *args, **kwargs)


Name Description Type/Default Value Required / Optional

Function to use for transforming the data. If a function, must either work when passed a DataFrame or when passed to DataFrame.apply.
Accepted combinations are:

  • function
  • string function name
  • list of functions and/or function names, e.g. [np.exp. 'sqrt']
  • dict of axis labels -> functions, function names or list of such.
function, str, list or dict Required
axis  If 0 or ‘index’: apply function to each column. If 1 or ‘columns’: apply function to each row. {0 or ‘index’, 1 or ‘columns’}
Default Value: 0
*args Positional arguments to pass to func.   Required
**kwargs Keyword arguments to pass to func.   Required

Returns: DataFrame
A DataFrame that must have the same length as self.

Raises: ValueError - If the returned DataFrame has a different length than self.


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