python - How to print a given number of decimal places?

Question

I want to print my result with a specific number of decimal places inside of a for loop where the value of it is the number of decimal places to be printed.

Below is a sample of the relevant part of the code:

for i in range (-15, -7):    
    print ('Valor do erro:' , 10**i,  'Valor da serie:', count, '------->', '%.16f' % adder(count))

标签： pythonpython-3.x

Answer 1

格式说明符可以嵌套：

>>> for i in range(1, 5):
...     print("{:.{}f}".format(1/i, i))
...
1.0
0.50
0.333
0.2500

在这里，1/i转到第一个（外部）{...}和i第二个（内部）{}。

但请注意，小数位数不能为负数。为此，您可能只想使用科学记数法。

>>> for i in range(-2, 3):
...    print("{:.2e}".format(10**i))
...
1.00e-02
1.00e-01
1.00e+00
1.00e+01
1.00e+02