How to accurately output JSON floating-point numbers in Python

Sometimes you need to use floating-point numbers in JSON, such as prices, coordinates, and so on. But the floating-point numbers in python are fairly inaccurate, such as the following code:
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#!/usr/bin/env python

Import JSON as JSON

data = [0.333, 0.999, 0.1]
Print Json.dumps (data)

The output results are as follows:
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$ python floatjson.py
[0.33300000000000002, 0.999, 0.10000000000000001]

Can you specify the output format of a floating-point number, such as two digits after the decimal point? There is an easy way to compare dirty, though:
Copy the Code code 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)

This results in the following output:
Copy the Code code as follows:

$ python floatjson.py
[0.333, 0.999, 0.100]

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