This question already has answers here:
Is integer division always equal to the floor of regular division?
(4 answers)
Closed 3 years ago.
I was making an integer to Boolean program and was dealing with some large numbers
The test case was - 15921396743627894741911
When I used
r/2 the output was 7.960698371813948e+21
int(r/2) gave me 7960698371813947736064
and r//2 gave me 7960698371813947370955
Why is the value for the last two cases so vastly different. Thank you
In Python 3, / does "true division", which returns a float, but floats have limited precision.
Related
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Python and Powers Math
(3 answers)
How do I do exponentiation in python? [duplicate]
(3 answers)
Closed last year.
Is it possible to type a squared number in python?
Or how to type for example 5 to the power of 2
number**power
As Joran Beasley said you only type **2 next to the number to take it to the power of 2.
In python we multiply with * so ** is multiplying two times, which is square. however *** is an error and **3 is cubic.
however you can also define a method
def power(number,n):
x=1
for n in range(n):
x=number*x
return x
print(power(5,8))
This question already has answers here:
What is the smallest number which can be represented in python?
(2 answers)
Is floating point math broken?
(31 answers)
Closed 2 years ago.
Why does the result of the next product yield the result 0?
print(3.944069389679206e-306*2.85043837e-46)
The product that results from that multiplication is too small for floats to hold.
Python uses double-precision floats, which can hold values from about 10 to the -308 to 10 to the 308 power.
This question already has answers here:
Is floating point math broken?
(31 answers)
Closed 2 years ago.
I am using python 3.8.5 to sum a list of floats as follows:
>> prices = [12.3, 11.99, 1.99, 5]
>> sum(prices)
31.279999999999998
here as you see, the sum function is returning a rounded result where the real sum is equal to 31.28. What sum has a same behaviour?
This is caused by floats implementation, not sum. You might use decimal.Decimal to avoid that problem.
import decimal
prices = [decimal.Decimal("12.3"), decimal.Decimal("11.99"), decimal.Decimal("1.99"), decimal.Decimal("5")]
print(sum(prices))
Output:
31.28
This question already has answers here:
Fixed digits after decimal with f-strings
(8 answers)
Closed 2 years ago.
I am writing confidence level using following code into my Image
text1="color is {}".format(f'Class #{i + 1}-{class_names[ind]}-Confidence: {100 * conf}%')
how do I limit my confidence number to two decimal places rather than the 10 or so it gives?
f'{100 * conf:.2f}' has to work
This question already has answers here:
Why does integer division yield a float instead of another integer?
(4 answers)
Closed 3 years ago.
Pretty new to python, facing a problem that requires basically the opposite of the remainder "%" function. For example, if I wanted to divide 81.5 by 20, my output would be 4. My best attempt is as follows:
amount = 81.504
round(amount, 2)
num20s = amount / 20
int(num20s)
I've tried several different combinations of the above code, but nothing has worked so far. This is the closest I've gotten to what I want, but it won't work in edge cases, and for some reason still represents the number with a ".0" at the end, so that last line must not be doing anything.
Integer division operator in python is "//".
>>> amount = 81.504
>>> amount // 20
Out[3]: 4.0
>>> int(amount // 20)
Out[4]: 4