Is there any way in which the execution of python statements can be made out of order

[Mohd Khan]

For example, can we execute the following script

a = 4
b = 3
k = 4 * c
c = a + b
print k

without getting a name error(since c is defined in the 4th line but called for in the 3rd line) i.e. first the 4th line should get executed then the third.

[dwblas]

first the 4th line should get executed then the third.

There are no "goto" statements in Python. So there is no way for the program to know what other execution path you wish it to take.

[Glenton]

The real question is why do you want it to do this? Maybe there's another way. But the short answer is "no"

[bvdet]

It's possible if you do it like this:

>>> a=4
>>> b=3
>>> k='4*c'
>>> c=a+b
>>> print eval(k)
28

[Glenton]

Ah, @bvdet, I like it. You could take this further, by making all the lines strings and using the exec command. You could do it inside a try except structure, so that the order is made correct, if possible.

Like this:

commands=['a=4','b=3','k=4*c','c=a+b']
 
j=0
while True:
    i=len(commands)
    if i==0:
        print "All commands executed"
        break
    if j>1000:
        print "Unable to resolve commands"
        break
    try:
        exec(commands[j%i])
        print commands[j%i], 'was executed successfully'
        commands=commands[:(j%i)]+commands[(j%i)+1:]  #remove executed command
    except:
        print commands[j%i], 'not yet executed'
        j+=1

which gives:

a=4 was executed successfully
b=3 was executed successfully
k=4*c not yet executed
c=a+b was executed successfully
k=4*c was executed successfully
All commands executed
>>>