Kay Schluehr wrote:
> Storing arguments away before they are evaluated doesn't work in
> Python. You have to hack the compiler in order to access the parsetree.
> You might take a look at the compiler package of the standard library
> that enables access to ASTs. Thus you could define lazy evaluation and
> just-in-time compilation of some particular ASTs. I do not recommend
> doing this for real purposes, but it is a good excercise and sooner or
> later you become an expert yourself :)
>
> Kay
I made some investigation and reached a (partial) solution to my
problem. It is inspired from a cookbook recipe but it only works for
generator expressions.:
import tokenize
import token
def magic_function(s):
cursor = None # to be set to the cursor of the connection
return_type = object # can be set to dict or list
_iterating = False # used in next()
readline = open(s.gi_frame.f_code.co_filename).readline
first_line = s.gi_frame.f_code.co_firstlineno
flag = False
source = '' # the source code
for t in
tokenize.generate_tokens(open(s.gi_frame.f_code.co_filename).readline):
# check all tokens until the last parenthesis is closed
t_type,t_string,(r_start,c_start),(r_end,c_end),line = t
t_name = token.tok_name[t_type]
if r_start == first_line:
if t_name == 'NAME' and t_string=="magic_function":
flag = True
res = t_string
start = 0 # number of parenthesis
continue
if flag:
source += ' '+t_string
if t_name == 'OP':
if t_string=='(':
start += 1
elif t_string == ')':
start -= 1
if start == 0:
break
return source[2:-2]
assert magic_function(i+2 for i in [1,2])=="i+2 for i in [1,2]"
or
print magic_function(i+2 for i in [1,2])
A general solution is possible and i am sure there are people around
that will provide such a solution
Alain
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