Object is not being defined outside the loop in python

Question

import json

xyz={"john": """{"name": "john","id":"123"}""","tom" : """{"name":"tom","id":"456"}"""}

class abc(object):
  def __init__ (self,**d):
    self.name=d['name'];
    self.id=d['id'];

def main():
   ks=xyz.keys()
   for j in ks:
      lm1="xyz['%s']" %(j)
      ds=eval(lm1);
      ds1=json.loads(ds)
      ln="%s=abc(**ds1)" %(j)
      print(ln)
      exec(ln);
      ln2="%s.name" %(j)
      print(eval(ln2));
   print(john.name)
   print(tom.id)

if __name__ == "__main__":
   main();

and the error is

tom=abc(**ds1)
tom
john=abc(**ds1)
john
Traceback (most recent call last):
  File "new6.py", line 26, in <module>
    main();
  File "new6.py", line 22, in main
    print(john.name)
NameError: name 'john' is not defined

why am i not being able to access "tom.name","john.name" in main() block? where did i do wrong? and how can it be done in much simpler way? (i actually have a json file, dont bother much about the "xyz")

@khelwood error in putting up the question...its my first time — Sandeep desai, Oct 12 '17 at 12:24
For me the program works fine as it is. No NameError if I run it. — Humbalan, Oct 12 '17 at 12:27
May be because,you might be running it in python2.* ,i want it in 3.* — Sandeep desai, Oct 13 '17 at 05:44

score 1 · Accepted Answer · answered Oct 12 '17 at 12:58

The behavior of this program is different between Python2.* and Python3*.

1.) xyz.keys() gives a list in Python2.7, but needs to be cast from the dict_keys class to a list in Python3.6.

2.) The behavior of exec is different between Python2.* and Python3.* See here for more details. Because of this, if you're running your program with Python3, john and tom haven't been defined, and you get an error when trying to access them.

Object is not being defined outside the loop in python

1 Answers1