python dataframe astype 字段类型转换方法_Python

python dataframe astype 字段类型转换方法

2021-01-30 00:14伴生伴熟 Python

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使用astype实现dataframe字段类型转换

									# -*- coding: UTF-8 -*-

									import pandas as pd

									df = pd.DataFrame([{'col1':'a', 'col2':'1'}, {'col1':'b', 'col2':'2'}])

									print df.dtypes

									df['col2'] = df['col2'].astype('int')

									print '-----------'

									print df.dtypes

									df['col2'] = df['col2'].astype('float64')

									print '-----------'

									print df.dtypes

输出结果：

									col1  object

									col2  object

									dtype: object

									-----------

									col1  object

									col2   int32

									dtype: object

									-----------

									col1   object

									col2  float64

									dtype: object

注：data type list

									Data type  Description

									bool_  Boolean (True or False) stored as a byte

									int_  Default integer type (same as C long; normally either int64 or int32)

									intc  Identical to C int (normally int32 or int64)

									intp  Integer used for indexing (same as C ssize_t; normally either int32 or int64)

									int8  Byte (-128 to 127)

									int16  Integer (-32768 to 32767)

									int32  Integer (-2147483648 to 2147483647)

									int64  Integer (-9223372036854775808 to 9223372036854775807)

									uint8  Unsigned integer (0 to 255)

									uint16 Unsigned integer (0 to 65535)

									uint32 Unsigned integer (0 to 4294967295)

									uint64 Unsigned integer (0 to 18446744073709551615)

									float_ Shorthand for float64.

									float16 Half precision float: sign bit, 5 bits exponent, 10 bits mantissa

									float32 Single precision float: sign bit, 8 bits exponent, 23 bits mantissa

									float64 Double precision float: sign bit, 11 bits exponent, 52 bits mantissa

									complex_  Shorthand for complex128.

									complex64  Complex number, represented by two 32-bit floats (real and imaginary components)

									complex128 Complex number, represented by two 64-bit floats (real and imaginary components)