Table Of Contents

Search

Enter search terms or a module, class or function name.

pandas.Series.astype

Series.astype(dtype, copy=True, errors='raise', **kwargs)[source]

Cast a pandas object to a specified dtype dtype.

Parameters:
dtype : data type, or dict of column name -> data type

Use a numpy.dtype or Python type to cast entire pandas object to the same type. Alternatively, use {col: dtype, …}, where col is a column label and dtype is a numpy.dtype or Python type to cast one or more of the DataFrame’s columns to column-specific types.

copy : bool, default True

Return a copy when copy=True (be very careful setting copy=False as changes to values then may propagate to other pandas objects).

errors : {‘raise’, ‘ignore’}, default ‘raise’

Control raising of exceptions on invalid data for provided dtype.

  • raise : allow exceptions to be raised
  • ignore : suppress exceptions. On error return original object

New in version 0.20.0.

kwargs : keyword arguments to pass on to the constructor
Returns:
casted : same type as caller

See also

to_datetime
Convert argument to datetime.
to_timedelta
Convert argument to timedelta.
to_numeric
Convert argument to a numeric type.
numpy.ndarray.astype
Cast a numpy array to a specified type.

Examples

>>> ser = pd.Series([1, 2], dtype='int32')
>>> ser
0    1
1    2
dtype: int32
>>> ser.astype('int64')
0    1
1    2
dtype: int64

Convert to categorical type:

>>> ser.astype('category')
0    1
1    2
dtype: category
Categories (2, int64): [1, 2]

Convert to ordered categorical type with custom ordering:

>>> cat_dtype = pd.api.types.CategoricalDtype(
...                     categories=[2, 1], ordered=True)
>>> ser.astype(cat_dtype)
0    1
1    2
dtype: category
Categories (2, int64): [2 < 1]

Note that using copy=False and changing data on a new pandas object may propagate changes:

>>> s1 = pd.Series([1,2])
>>> s2 = s1.astype('int64', copy=False)
>>> s2[0] = 10
>>> s1  # note that s1[0] has changed too
0    10
1     2
dtype: int64
Scroll To Top