nameof not working inside of for loop

[tbrodbeck]

If I run this code the first call on a variable can be processed. But if I call it inside a for loop I get an error.

import varname
test = {}
print(varname.nameof(test))
for i in [0]:
  print(varname.nameof(test))

test
---------------------------------------------------------------------------
VarnameRetrievingError                    Traceback (most recent call last)
<ipython-input-39-f74218a72604> in <module>
      2 print(varname.nameof(test))
      3 for i in [0]:
----> 4   print(varname.nameof(test))

~/dev/textSum/.direnv/python-3.8.3/lib/python3.8/site-packages/varname.py in nameof(*args)
    183     if not exec_obj.node:
    184         # we cannot do: assert nameof(a) == 'a' in pytest
--> 185         raise VarnameRetrievingError("Callee's node cannot be detected.")
    186 
    187     assert isinstance(exec_obj.node, ast.Call)

VarnameRetrievingError: Callee's node cannot be detected.

Tested on macOS Catalina with python 3.8.3

[pwwang]

Fixed at v0.2.0.
Feel free the reopen if you have any related questions.

[pwwang]

@alexmojaki
Any thoughts on this? Looks like recent PRs break this.

In [1]: import varname 
   ...: test = {} 
   ...: print(varname.nameof(test)) 
   ...: for i in [0]: 
   ...:   print(varname.nameof(test)) 
   ...:                                                                                                
test
---------------------------------------------------------------------------
VarnameRetrievingError                    Traceback (most recent call last)
<ipython-input-1-7b4a24e26b47> in <module>
      3 print(varname.nameof(test))
      4 for i in [0]:
----> 5   print(varname.nameof(test))
      6 

/path/to/python-varname/varname.py in nameof(_caller, *args)
    201         tuple|str: The names of variables passed in
    202     """
--> 203     node = _get_node(_caller - 1)
    204     if not node:
    205         if len(args) == 1:

/path/to/python-varname/varname.py in _get_node(caller)
    299     if exet.source.text and exet.source.tree:
    300         raise VarnameRetrievingError(
--> 301             "Couldn't retrieve the call node. "
    302             "This may happen if you're using some other AST magic at the "
    303             "same time, such as pytest, ipython, macropy, or birdseye."

VarnameRetrievingError: Couldn't retrieve the call node. 
This may happen if you're using some other AST magic at the same time, 
such as pytest, ipython, macropy, or birdseye.

[alexmojaki]

Looks like you're using ipython

[pwwang]

@alexmojaki
@tbrodbeck We gave up support for ipython, and other environments where other AST magics apply. Since we can't reliably detect the ast node. See the discussions around this

Try to switch to a normal python environment.

[alexmojaki]

I have fixed this issue in executing. pip install -U executing and it should be resolved.

You should still try to avoid using varname in ipython, support for it will always be somewhat shaky. I fixed this because executing is also a dependency of ipython itself now for displaying nicer tracebacks. Fortunately when executing doesn't work in that context in ipython, you just get a slightly less informative traceback, not an exception like with varname.

[pwwang]

@alexmojaki
Which version of executing is supporting this?

[alexmojaki]

0.5.2, the latest version, released last night. Why do you ask? I don't think varname should require a specific version.

[pwwang]

@alexmojaki
No, I am not requiring a specific version of executing. I just want a number here so that when something has the same problem, I can direct him to upgrade executing to ^0.5.2.

[alexmojaki]

OK but in general encourage upgrading to the latest version. Most people won't even know they have it installed.

[pwwang]

@alexmojaki
True. Just in case.

[mmarras]

So how to use varname in a loop then?

import varname 

var1 = 1
var2 = 2

for var in [var1,var2]:
    print(varname.nameof(var))

'var', 'var'

Of course I want 'var1', 'var2'.