Looping in Python

For loops

for item in iterable_object:
	...
 
for char in "hello":
	print("char:" + char)
 
for num in range(1,8): #(1-7)
	print(num)

• iterable_object
  • some kind of collection of items
  • List (python), range
• item
  • a new variable that can be called whatever you want
  • references the current position of our iterator within the iterable

Using _

You can use _ to indicate that the loop variable is not used within the loop’s body

for _ in range(5):
    print("Hello!")

While loop

count = 0
while count < 5:
    print(f"Count is: {count}")
    count += 1 # Increment count to eventually make the condition False
print("Loop finished.")

• Just a standard while loop lol

range

• Generates an ordered sequence of numbers
• immutable, NOT A LIST, but a special iterable object
• commonly used in for loops

# one number (end)
range(7) # 0-6
 
# two numbers (start, end)
range(0,7) # 0 - 6
 
# three numbers (start, end, step)
range(1,11,2) # 1,3,5,7,9
range(6,0,-1) # 6,5,4,3,2,1
 
# range to list
r = range(0,6) # 0,1,2,3,4,5
list(r) # [0,1,2,3,4,5]