How can I print an integer number displaying 4 decimal digits?

Question

print(round(mas[i],4))

这仅适用于浮点数，不适用于整数。

Answer 1

Format your number using format() :

format(mas[i], '.4f')

This formats numbers (including integers) to 4 decimal places. See the Format Specification Mini-Language documentation .

Demo:

>>> print(format(16, '.4f'))
16.0000
>>> print(format(4.242422, '.4f'))
4.2424

If the number is part of a larger string, you can use the format specification in a str.format() format string , using placeholders:

'Your frobnar has been opfritzed to {:.4f} hafnavz'.format(mas[i])

Answer 2

To be complete, you can also use the printf style formating :

>>> '%0.4f' % 4
'4.0000'
>>> '%0.4f' % 4.56789
'4.5679'
>>> '%0.4f' % .1
'0.1000'

As stated in the documents, it can be quirky with tuples, but can also be faster.