def cast(arr, target_type, safe=True):
"""
Cast array values to another data type. Can also be invoked as an array
instance method.
Parameters
----------
arr : Array or ChunkedArray
target_type : DataType or type string alias
Type to cast to
safe : bool, default True
Check for overflows or other unsafe conversions
Examples
--------
>>> from datetime import datetime
>>> import pyarrow as pa
>>> arr = pa.array([datetime(2010, 1, 1), datetime(2015, 1, 1)])
>>> arr.type
TimestampType(timestamp[us])
You can use ``pyarrow.DataType`` objects to specify the target type:
>>> cast(arr, pa.timestamp('ms'))
<pyarrow.lib.TimestampArray object at 0x7fe93c0f6910>
[
2010-01-01 00:00:00.000,
2015-01-01 00:00:00.000
]
>>> cast(arr, pa.timestamp('ms')).type
TimestampType(timestamp[ms])
Alternatively, it is also supported to use the string aliases for these
types:
>>> arr.cast('timestamp[ms]')
<pyarrow.lib.TimestampArray object at 0x10420eb88>
[
1262304000000,
1420070400000
]
>>> arr.cast('timestamp[ms]').type
TimestampType(timestamp[ms])
Returns
-------
casted : Array
"""
if target_type is None:
raise ValueError("Cast target type must not be None")
if safe:
options = CastOptions.safe(target_type)
else:
options = CastOptions.unsafe(target_type)
return call_function("cast", [arr], options)
def cast(arr, target_type=None, safe=None, options=None):
"""
Cast array values to another data type. Can also be invoked as an array
instance method.
Parameters
----------
arr : Array-like
target_type : DataType or str
Type to cast to
safe : bool, default True
Check for overflows or other unsafe conversions
options : CastOptions, default None
Additional checks pass by CastOptions
Examples
--------
>>> from datetime import datetime
>>> import pyarrow as pa
>>> arr = pa.array([datetime(2010, 1, 1), datetime(2015, 1, 1)])
>>> arr.type
TimestampType(timestamp[us])
You can use ``pyarrow.DataType`` objects to specify the target type:
>>> cast(arr, pa.timestamp('ms'))
<pyarrow.lib.TimestampArray object at ...>
[
2010-01-01 00:00:00.000,
2015-01-01 00:00:00.000
]
>>> cast(arr, pa.timestamp('ms')).type
TimestampType(timestamp[ms])
Alternatively, it is also supported to use the string aliases for these
types:
>>> arr.cast('timestamp[ms]')
<pyarrow.lib.TimestampArray object at ...>
[
2010-01-01 00:00:00.000,
2015-01-01 00:00:00.000
]
>>> arr.cast('timestamp[ms]').type
TimestampType(timestamp[ms])
Returns
-------
casted : Array
"""
safe_vars_passed = (safe is not None) or (target_type is not None)
if safe_vars_passed and (options is not None):
raise ValueError("Must either pass values for 'target_type' and 'safe'"
" or pass a value for 'options'")
if options is None:
target_type = pa.types.lib.ensure_type(target_type)
if safe is False:
options = CastOptions.unsafe(target_type)
else:
options = CastOptions.safe(target_type)
return call_function("cast", [arr], options)