Example 1: for in range loop python
#there are two possibilities for a for loop
#first one is with a range()
#range() just generates lists after the following pattern
print(range(4))
>>> [0,1,2,3]
print(range(1,4))
>>> [1,2,3]
print(range(2,10,2))
>>> [2,4,6,8]
#and what the for does then is that it lets a variable (in my example x) cycle trough the list given after in
for x in range(2,10,2):
print(x)
>>> 2
>>> 4
>>> 6
>>> 8
#so the code in the loop gets executed for every value in the given list after in
#you can also use for ... in for custom lists
#example 1:
list1 = [1,2,50,2]
for x in list1:
print(x)
>>> 1
>>> 2
>>> 50
>>> 2
#example 2
list2 = ["bananas", "apples", "pears"]
for x in list2:
print(x)
>>> "bananas"
>>> "apples"
>>> "pears"
Example 2: for i in range start
for i in range([start], stop[, step])
Example 3: range python 3
# range(start, stop, step)
# start = index to begin at (INCLUSIVE)
# stop = generate numbers up to, but not including this number (EXCLUSIVE)
# step = (can be omitted) difference between each number in the sequence
arr = [19,5,3,22,13]
# range(stop)
for i in range(len(arr)):
print(arr[i]) # prints: 19, 5, 3, 22, 13
# range(start, stop)
for i in range(2, len(arr)):
print(arr[i]) # prints: 3, 22, 13
# range(start, stop, step)
for i in range(0, len(arr), 2):
print(arr[i]) # prints: 19, 3, 13
# reverse:
for i in range(len(arr)-1, -1, -1):
print(arr[i])
Example 4: range python start at 1
>>> def range1(start, end):
... return range(start, end+1)
...
>>> range1(1, 10)
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]