break for loop in Python
Question:
is it possible to break a for loop in Python, without break command?
I’m asking this question in order to compare it with C++ for loop, in which actually checks a condition each time.
i.e. it’s possible to break a for loop in C++ like below:
for(int i=0; i<100; i++)
i = 1000; // equal to break;
is it possible to do the same in Python?
for i in range(0,100):
i = 10000 // not working
Answers:
Python’s for is really a "for each" and is used with iterables, not loop conditions.
Instead, use a while statement, which checks the loop condition on each pass:
i = 0
while i < 1000:
i = 1000
Or use an if statement paired with a break statement to exit the loop:
for i in range(1000):
if i == 10:
break
Use a while loop for that purpose:
i = 0
while i < 100:
i = 1000
This won’t work (as you’ve noticed). The reason is that, in principle, you are iterating the elements of a list of ascending numbers (whether that is really true depends on if you’re using python 2 or 3). You can use the ‘break’ keyword to break out of a loop at any time, although using it in excess might make it hard to follow your code.
No, for doesn’t work like that in Python. for iterates over a list (in this case) or other container or iterable. for i in range(0, 100) doesn’t mean “increment i until i is greater than or equal to 100″, it means “set i to successive items from a list of these 100 items until the list is exhausted.”
If i is 50, then the next item of the list is still 51, regardless of what you may set i to.
break is better anyway.
You might have to settle for the break statement:
http://docs.python.org/tutorial/controlflow.html
for i in range(0,100):
print i
if i == 10:
break
is it possible to break a for loop in Python, without break command?
I’m asking this question in order to compare it with C++ for loop, in which actually checks a condition each time.
i.e. it’s possible to break a for loop in C++ like below:
for(int i=0; i<100; i++)
i = 1000; // equal to break;
is it possible to do the same in Python?
for i in range(0,100):
i = 10000 // not working
Python’s for is really a "for each" and is used with iterables, not loop conditions.
Instead, use a while statement, which checks the loop condition on each pass:
i = 0
while i < 1000:
i = 1000
Or use an if statement paired with a break statement to exit the loop:
for i in range(1000):
if i == 10:
break
Use a while loop for that purpose:
i = 0
while i < 100:
i = 1000
This won’t work (as you’ve noticed). The reason is that, in principle, you are iterating the elements of a list of ascending numbers (whether that is really true depends on if you’re using python 2 or 3). You can use the ‘break’ keyword to break out of a loop at any time, although using it in excess might make it hard to follow your code.
No, for doesn’t work like that in Python. for iterates over a list (in this case) or other container or iterable. for i in range(0, 100) doesn’t mean “increment i until i is greater than or equal to 100″, it means “set i to successive items from a list of these 100 items until the list is exhausted.”
If i is 50, then the next item of the list is still 51, regardless of what you may set i to.
break is better anyway.
You might have to settle for the break statement:
http://docs.python.org/tutorial/controlflow.html
for i in range(0,100):
print i
if i == 10:
break