http://dsas.blog.klab.org/archives/51742727.html

dis.py

import dis


def foriter():
    ilist = []
    for i in range(3):
        ilist.append(i)
    return ilist

dis.dis(foriter)
print "-----------------------------------------------------------------------"


def listc():
    ilist = [i for i in range(3)]
    return ilist

dis.dis(listc)

result.txt

  5           0 BUILD_LIST               0
              3 STORE_FAST               0 (ilist)

  6           6 SETUP_LOOP              33 (to 42)
              9 LOAD_GLOBAL              0 (range)
             12 LOAD_CONST               1 (3)
             15 CALL_FUNCTION            1
             18 GET_ITER            
        >>   19 FOR_ITER                19 (to 41)
             22 STORE_FAST               1 (i)

  7          25 LOAD_FAST                0 (ilist)
             28 LOAD_ATTR                1 (append)
             31 LOAD_FAST                1 (i)
             34 CALL_FUNCTION            1
             37 POP_TOP             
             38 JUMP_ABSOLUTE           19
        >>   41 POP_BLOCK           

  8     >>   42 LOAD_FAST                0 (ilist)
             45 RETURN_VALUE        
-----------------------------------------------------------------------
 15           0 BUILD_LIST               0
              3 LOAD_GLOBAL              0 (range)
              6 LOAD_CONST               1 (3)
              9 CALL_FUNCTION            1
             12 GET_ITER            
        >>   13 FOR_ITER                12 (to 28)
             16 STORE_FAST               0 (i)
             19 LOAD_FAST                0 (i)
             22 LIST_APPEND              2
             25 JUMP_ABSOLUTE           13
        >>   28 STORE_FAST               1 (ilist)

 16          31 LOAD_FAST                1 (ilist)
             34 RETURN_VALUE