使用Python在列表中查找偶数个数

Question

I am searching for the most pythonic way to check, whether one or more elements in a list are even multiples of a predefined number with a predefined tolerance. An example is given below:

myNumber=3.5
myList=[0,0.5,1,1.5,2,2.5,3,3.5,4,4.5,5,5.5,6,6.5,7,7.5,8,8.5,9,9.5]
myTolerance=0.5

myResult=[0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,0,0,0,0]

Any suggestions are very appreciated.

Answer 1

How about

from numpy import mod, floor
withinTolAbove=[int(mod(number, myNumber) <= myTolerance and
                mod(floor(number / myNumber), 2) == 0) for number in myList]
withinTolBelow=[int(mod(number + myTolerance, myNumber) <= myTolerance and
                mod(floor((number + myTolerance) / myNumber), 2) == 0) for number in myList]
myResult=[max(i1, i2) * int(number > myTolerance) for i1, i2, number in zip(withinTolAbove, withinTolBelow, myList)]

The first part determines if the division is within the tolerance of an integer and the second part figures out if this integer is divisible by 2.

Answer 2

How about

print print([int(abs(x - round(x / myNumber) * myNumber) <= myTolerance and round(x / myNumber) > 1.5) for x in myList])

Output:

[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0]