operating_systems = ["windows", "mac", "linux"] for os in operating_systems:     print(os)`  

# output windows mac linux 

operating_systems = ["windows", "mac", "linux"] for i in range(len(operating_systems)):     print(f"index {i}: {operating_systems[i]}") 

# output index 0: windows index 1: mac index 2: linux 

operating_systems = ["windows", "mac", "linux"] for index, os in enumerate(operating_systems):     print(f"index is {index} and value is {os}") 

# output index is 0 and value is windows index is 1 and value is mac index is 2 and value is linux 

operating_systems = ["windows", "mac", "linux"] i = 0 # inital condition, required to start while i < len(operating_systems):     print(f"while looping {i} got the value {operating_systems[i]}")     i = i + 1 # this is very important, dont forget about infinite loops 

# output while looping 0 got the value windows while looping 1 got the value mac while looping 2 got the value linux 

operating_systems = ["windows", "mac", "linux"] iterator = iter(operating_systems) while true:     try:         os = next(iterator)         print(f"consumed form iterator {os}")     except stopiteration:         print("consumed all from iterator")         break 

# output consumed form iterator windows consumed form iterator mac consumed form iterator linux consumed all from iterator 

# hack to avoid stopiteration iterator = iter(operating_systems) end_of_list = object() reached_end = false while not reached_end:     os = next(iterator, end_of_list)# a predefined object as end of the list     if os != end_of_list:         print(os)     else:         reached_end = true 

operating_systems = ["windows", "mac", "linux"] os_uppercase = [os.upper() for os in operating_systems] print(os_uppercase)  

# output ['windows', 'mac', 'linux'] 

import itertools operating_systems = ["windows", "mac", "linux"] for item in itertools.cycle(operating_systems):       print(item) # infinite cycling loopmake sure to have proper boundary condition to break 

# output windows mac linux windows mac linux windows mac linux windows mac linux windows ....... infinite loop 

operating_systems = ["windows", "mac", "linux"] mobile_operating_systems = ["android", "ios"]  for os, mobile_os in zip(operating_systems,mobile_operating_systems):     print(os, mobile_os) 

# output windows android mac ios 

operating_systems = ["windows", "mac", "linux"] for reversed_os in reversed(operating_systems):     print(reversed_os) 

# Output linux mac windows