reliable to read loop variable after loop in Python -

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• short description of scoping rules? 7 answers

is safe read loop variable after loop (using python 2)? purpose check how many iterations in loop done.

here code show idea:

a=[1,2,3,4,5]  in range(len(a)):     if a[i] == 2:         break  print # output 1, safe read here? 

yes, fine read there. because when create for loop, internally, has mechanism create indexer (in case being i) , increases 1 one assigning new value every time. thus, can use i after for loop. after:

a=[1,2,3,4,5]  in range(len(a)):     if a[i] == 2:         break     

i isn't dropped. drop i, can use del keyword:

a=[1,2,3,4,5]  in range(len(a)):     if a[i] == 2:         break      del #deleted here  print # give error! 

while replace is, need redefine it:

a=[1,2,3,4,5]  in range(len(a)):     if a[i] == 2:         break      = [] #now list, not integer anymore  print # give different result: [] 

similarly, example, if create list in if block:

if == 0: #suppose enter block    = [] #a created here  a.append(b) #but can used here, assuming previous if entered 

this how python works.

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