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I was reading the lexical definition for valid decimal string syntax in the documentation for decimal.Decimal and the following struck me as kind of odd:
nan ::= 'NaN' [digits] | 'sNaN' [digits]
This looked really strange to me, but apparently digits can be included after 'NaN' without any issues, but any character besides digits after 'NaN' raises InvalidOperation.
>>> Decimal('NaN10')
Decimal('NaN10')
So I have a few questions about this:
NaN?NaN with digits behave differently than a "normal" NaN?NaN with digits besides initializing it that way?Decimal class where NaN can be followed by digits?Thanks!
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Use the round() function to print a float to 6 decimal places, e.g. print(round(my_float, 6)) . The round() function will round the floating-point number to 6 decimal places and will return the result.
Floats are decimals, positive, negative and zero. Floats can also be numbers in scientific notation which contain exponents. In Python, a float can be defined using a decimal point .
In Python, there is a module called Decimal, which is used to do some decimal floating point related tasks. This module provides correctly-rounded floating point arithmetic. To use it at first we need to import it the Decimal standard library module. import decimal.
It is an IEEE-754 feature to distinguish between different kinds of NaNs (the "payload"). The digits are encoded into the mantissa of the number:
>>> Decimal("NaN456").as_tuple()
DecimalTuple(sign=0, digits=(4, 5, 6), exponent='n')
>>> Decimal("NaN123").as_tuple()
DecimalTuple(sign=0, digits=(1, 2, 3), exponent='n')
>>> Decimal("NaN").as_tuple()
DecimalTuple(sign=0, digits=(), exponent='n')
The sole purpose of the payload is for diagnosis. These NaNs are no different from "normal" NaNs.
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