Article Outline
In this article we introduce Python's loop, the program in general are executed sequentially. Sequentially means in sequential order (top down):
do A
do B
do C
In a variety of programming languages, control structures allows for more complex execution paths.
Loop allows us to perform a statement or group of statements repeatedly, the following is the general form in most programming languages loop statement:
Python is provided for and while loops (not do..while loop in Python):
Circulation type | Description |
---|---|
The while loop | determines the given condition is true. When the execution loop, or exit the loop. |
For loop | Repeat statement |
[Nested loop] | You can be nested for loop while loop body |
The while loop in code:
>>> index = 0
>>> n = 10
>>> while index < n:
... print(index)
... index = index + 1
...
0
1
2
3
4
5
6
7
8
9
The for loop:
>>> for i in range(1,3):
... print(i)
...
1
2
The nested for loop:
>>>
>>> for x in range(1,10):
... for y in range(1,10):
... print(f"({x},{y})")
loop control statements
Loop control statements can change the order of statement execution. Python loop control supports the following statement:
Control statements | Description |
---|---|
Break Statement | Terminates the loop during the execution of statement block, and jump out of the entire cycle |
Continue Statement | Terminates the current execution loop statement block, out of the cycle, the next cycle execution. |
Pass sentence | pass an empty statement, in order to maintain the integrity of the program structure. |