Infinite loop
If the conditional judgment statement is always true, the loop will execute indefinitely.
The following example
#! /usr/bin/python
# - *- coding: UTF-8-*-var=1whilevar==1: #This condition is always true, and the loop will execute indefinitely
num =raw_input("Enter a number :")
print "You entered: ", num
print "Good bye!"
The output of the above example:
Enter a number :20
You entered:20
Enter a number :29
You entered:29
Enter a number :3
You entered:3
Enter a number between :Traceback(most recent call last):
File "test.py", line 5,in<module
num =raw_input("Enter a number :")
KeyboardInterrupt
< /module
Note: You can use CTRL+C to interrupt the infinite loop above.
python while 1 vs while True
Before Python 3.0, their implementation was different:
While 1, python will optimize, and each loop will not check the condition of 1, so the performance will be better
While True, before python 3k, True is not a reserved word, users can True=0, so each time you have to compare the value of True
After Python 3.0, True/False have become reserved words.
True =10
Will report an error
Therefore, after python 3, while 1 and while True have the same effect, they will all be optimized by the interpreter
Content supplement
Python infinite loop: In the while loop statement, you can achieve an infinite loop by making the judgment condition never reach False.
Conditional expression:
# var=1
# whilevar==1: #Expression is always True
# print("var = 1")
# # var=1
# ...
# # var=1
Boolean value:
# while True:
# print("Condition is true")
# # Condition is true
# ...
# # Condition is true
So far, this article on the conditions for infinite loops in Python is introduced. For more information about the conditions of infinite loops in Python, please search ZaLou.Cn
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