python圆形numpy数组，尾随0到一定的小数位数

Question

I have a np array freq_vector filled with floating numbers. For example freq_vector[0][0] is 200.00000000000003

I want to limit it to 4 decimals, then convert it to string for other usage.

When I do round(freq_vector[0][0], 4) , the result is 200.0 , rather than 200.0000

How can I get 200.0000 ?

Answer 1

In Python, 200.0000 is the same as 200.0 . Both are floating point numbers with the same value. Since you want to convert them to strings, you can use the format method, such as the following:

"{:.4f}".format(freq_vector[0][0])

Using the round() function is not necessary in this case.

In Python 3, you can use the simpler "f-string" syntax:

f"{freq_vector[0][0]:.4f}"

You can find more information about this feature at PEP 498 .