This article describes how to accurately output a JSON floating point number in python. For more information about how to use floating point numbers in JSON, such as price and coordinates. But the floating point number in python is quite inaccurate, such as the following code:
The code is as follows:
#! /Usr/bin/env python
Import json as json
Data = [0.333, 0.999, 0.1]
Print json. dumps (data)
The output result is as follows:
The code is as follows:
$ Python floatjson. py
[0.33300000000000002, 0.999, 0.10000000000000001]
Can I specify the output format of a floating point number, for example, to the last two digits of the decimal point? There is a simple method, although compared with dirty:
The code is as follows:
#! /Usr/bin/env python
Import json
Json. encoder. FLOAT_REPR = lambda x: format (x, '. 3f ')
Data = [0.333, 0.999, 0.1]
Print json. dumps (data)
The output result is as follows:
The code is as follows:
$ Python floatjson. py
[0.333, 0.999, 0.100]
