Example 1: python for loop backwards
for i in range(len(item)-1, -1, -1):
print(item[i])
Example 2: reverse for loop python
# 1.
for i in reversed(range(3)): # output: 0
print(i) # 1
# 2
# works with arrays as well , reversed(arr)
# 2.
# another alternative is
arr = [1,2,3]
# note: arr[start : end : step]
for i in arr[::-1]: # output: 0
print(i) # 1
# 2
# 3.
# last alternative i don't recommened!
# note: range(start, end, step)
for i in range(len(arr) - 1, -1 , -1): # output: 0
print(i) # 1
# 2
# read more on range() to understand even better how it works has the same rules as the arrays
Example 3: python range reverse
When you call range() with three arguments, you can choose not only
where the series of numbers will start and stop but also how big the
difference will be between one number and the next.
range(start, stop, step)
If your 'step' is negative and 'start' is bigger than 'stop', then
you move through a series of decreasing numbers.
for i in range(10,0,-1):
print(i, end=' ')
# Output: 10 9 8 7 6 5 4 3 2 1
Example 4: python for loop reverse
my_list = [1, 2, 3]
my_list.reverse() # my_list is modified
print(my_list) # '[3, 2, 1]'
my_revert = my_list[::-1] # my_list stays [3, 2, 1]
print(my_revert) # '[1, 2, 3]'
# Item by item reverse with range(<start>, <end>, <step>)
for i in range(len(my_list), 0, -1): # my_list is [3, 2, 1]
print(my_list[i-1]) # '1' '2' '3'
for i in reversed(range(len(my_list))):
print(my_list[i]) # '1' '2' '3'
Example 5: how to count backwards in for loop python
# for i in range(start, end, step)
for i in range(5, 0, -1):
print(i)
5
4
3
2
1
Example 6: reverse iteration python
for i in range(10, 0, -1):
#reverses backwards from 10