+= in list comprehension code example
Example 1: python list comprehension
#example: removing common elements found in `a` from `b`.
a = [1,2,3,4,5]
b = [5,6,7,8,9]
# desired output: [1,2,3,4]
# gets each item found in `a` AND not in `b`
print([i for i in a if i not in b])
Example 2: list comprehension
# List comprehension
list_comp = [i+3 for i in range(20)]
# above code is similar to
for i in range(20):
print(i + 3)