Good python equivalent to C goto

[Kurien Mathew]

Hello,

Any suggestions on a good python equivalent for the following C code:

while (loopCondition)
{
if (condition1)
goto next;
if (condition2)
goto next;
if (condition3)
goto next;
stmt1;
stmt2;
next:
stmt3;
stmt4;
}

Thanks
Kurien

[Reedick, Andrew]

-----Original Message-----
From: py************* *************** ****@python.org [mailto:python-
li************* ************@py thon.org] On Behalf Of Kurien Mathew
Sent: Saturday, August 16, 2008 5:21 PM
To: py*********@pyt hon.org
Subject: Good python equivalent to C goto

Hello,

Any suggestions on a good python equivalent for the following C code:

while (loopCondition)
{
if (condition1)
goto next;
if (condition2)
goto next;
if (condition3)
goto next;
stmt1;
stmt2;
next:
stmt3;
stmt4;
}

=============== ============
Use a flag and a one loop for loop
while loopCondition:
flag = False
for i in range(1):
if condition1:
break
if condition2:
break
if condition3:
break
stmt1
stmt2
flag = True
if not flag:
stmt3
stmt4
=============== ============
Or just a straight flag

while ( loopCondition ):
flag = False

if (condition1)
flag = True # goto next;
if (not flag and condition2)
flag = True # goto next;
if (not flag and condition3)
flag = True # goto next;

if not flag:
stmt1
stmt2
else
stmt3
stmt4

*****

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[Paul McGuire]

On Aug 17, 1:09*pm, Matthew Fitzgibbons <eles...@nienna .orgwrote:

Kurien Mathew wrote:

Hello,

Any suggestions on a good python equivalent for the following C code:

while (loopCondition)
{
* * if (condition1)
* * * * goto next;
* * if (condition2)
* * * * goto next;
* * if (condition3)
* * * * goto next;
* * stmt1;
* * stmt2;
next:
* * stmt3;
* * stmt4;
*}

Thanks
Kurien
--
http://mail.python.org/mailman/listinfo/python-list

I would not be too happy if I saw C code like that in my repository.
This is equivalent:

while (loopCondition) {
* * *if (!(condition1 || condition2 || condition3)) {
* * * * *stmt1;
* * * * *stmt2;
* * *}
* * *stmt3;
* * *stmt4;

}

In Python:

while (loopCondition) :
* * *if not (condition1 or condition2 or condition3):
* * * * *stmt1
* * * * *stmt2
* * *stmt3
* * *stmt4

If stmt3 and stmt4 are error cleanup code, I would use try/finally.

while loopCondition:
* * *try:
* * * * *if condition1:
* * * * * * *raise Error1()
* * * * *if condition2:
* * * * * * *raise Error2()
* * * * *if condition3:
* * * * * * *raise Error3()
* * * * *stmt1
* * * * *stmt2
* * *finally:
* * * * *stmt3
* * * * *stmt4

This will also bail out of the loop on and exception and the exception
will get to the next level. If you don't want that to happen, put an
appropriate except block before the finally.

-Matt- Hide quoted text -

- Show quoted text -

Close, but there is no reason for the conditions to raise anything,
they can just use the continue statement:

i = 20
while i 0:
try:
if i % 2:
continue
if i % 3:
continue
print i, "is even and a multiple of 3"
finally:
i -= 1

Prints:
18 is even and a multiple of 3
12 is even and a multiple of 3
6 is even and a multiple of 3

I think this is closest to the OP's stated requirements.

-- Paul

[Matthew Fitzgibbons]

Paul McGuire wrote:

On Aug 17, 1:09 pm, Matthew Fitzgibbons <eles...@nienna .orgwrote:

>Kurien Mathew wrote:

>>Hello,
Any suggestions on a good python equivalent for the following C code:
while (loopCondition)
{
if (condition1)
goto next;
if (condition2)
goto next;
if (condition3)
goto next;
stmt1;
stmt2;
next:
stmt3;
stmt4;
}
Thanks
Kurien
--
http://mail.python.org/mailman/listinfo/python-list

I would not be too happy if I saw C code like that in my repository.
This is equivalent:

while (loopCondition) {
if (!(condition1 || condition2 || condition3)) {
stmt1;
stmt2;
}
stmt3;
stmt4;

}

In Python:

while (loopCondition) :
if not (condition1 or condition2 or condition3):
stmt1
stmt2
stmt3
stmt4

If stmt3 and stmt4 are error cleanup code, I would use try/finally.

while loopCondition:
try:
if condition1:
raise Error1()
if condition2:
raise Error2()
if condition3:
raise Error3()
stmt1
stmt2
finally:
stmt3
stmt4

This will also bail out of the loop on and exception and the exception
will get to the next level. If you don't want that to happen, put an
appropriate except block before the finally.

-Matt- Hide quoted text -

- Show quoted text -

Close, but there is no reason for the conditions to raise anything,
they can just use the continue statement:

i = 20
while i 0:
try:
if i % 2:
continue
if i % 3:
continue
print i, "is even and a multiple of 3"
finally:
i -= 1

Prints:
18 is even and a multiple of 3
12 is even and a multiple of 3
6 is even and a multiple of 3

I think this is closest to the OP's stated requirements.

-- Paul
--
http://mail.python.org/mailman/listinfo/python-list

I'm aware my example where I raised exceptions was functionally
different ("This will bail out of the loop on an exception and the
exception will get to the next level.") Just thinking in terms of
telling the caller something went wrong. The other examples were
functionally equivalent, however.

Still, this is the best way so far. :) I never thought of using continue
with finally. It gets added to my Python tricks file for future use.

-Matt