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in Python

Basically, I'm converting a float to an int, but I don't always have the expected value.

Here's the code I'm executing:

x = 2.51

print("--------- 251.0")

y = 251.0

print(y)

print(int(y))

print("--------- 2.51 * 100")

y = x * 100

print(y)

print(int(y))

print("--------- 2.51 * 1000 / 10")

y = x * 1000 / 10

print(y)

print(int(y))

print("--------- 2.51 * 100 * 10 / 10")

y = x * 100 * 10 / 10

print(y)

print(int(y))

x = 4.02

print("--------- 402.0")

y = 402.0

print(y)

print(int(y))

print("--------- 4.02 * 100")

y = x * 100

print(y)

print(int(y))

print("--------- 4.02 * 1000 / 10")

y = x * 1000 / 10

print(y)

print(int(y))

print("--------- 4.02 * 100 * 10 / 10")

y = x * 100 * 10 / 10

print(y)

print(int(y))

And here's the result (first value is the result of the operation, second value is int() of the same operation):

--------- 251.0

251.0

251

--------- 2.51 * 100

251.0

250

--------- 2.51 * 1000 / 10

251.0

251

--------- 2.51 * 100 * 10 / 10

251.0

250

--------- 402.0

402.0

402

--------- 4.02 * 100

402.0

401

--------- 4.02 * 1000 / 10

402.0

401

--------- 4.02 * 100 * 10 / 10

402.0

401

2.51 and 4.02 are the only values that lead to that strange behaviour on the 2.50 -> 5.00 range. Every other two digits value in that range converts to int without any problem when given the same operations.

So, what am I missing that leads to those results? I'm using Python 2.7.2 by the way.

by (106k points)

To do Python float to int conversion you can use the below-mentioned code:-

The int() function simply truncates the number at the decimal point, giving 250. Use

int(round(2.51*100))

To know more about this you can have a look at the following video tutorial:-