I am trying to identify the import module name which is dependent by a variable in the script.
ex:
import module1
import module2
x = module1.func()
y = x.func()
given y, my output should be y -> x -> module1 and the respective line num.
Can someone help me figure this out? Just now started exploring this with AST.
Just using ast is not going to be helpful in a lot of situations. You
need to include some kind of (simulated) execution, akin of exec().
For example, what can the ast tell from this Python program, which outputs
a string of digits? The identifier "digits" seems to come out of thin air
in the syntax tree.
exec('from string import digits')
mystr = digits
print(mystr)
And, to support the argument of execution needed, the following program
would have to result in output nums -> int, but just using a syntax tree, it
would probably output nums -> string | int.
import string
nums = string.digits
if True:
nums = 0
print(nums)
Now, what you are asking can still be done, but rather than solve it with
abstract syntax trees, you would have more success using trace as a
starting point, and enhance the data collected in the various tracing calls.
ast for listing "where used" of libraries. But that's the easy part. Evaluating true library dependency for each variable is much harder.Your problem would be that your dependencies change dynamically. They are simply static dependencies and keeping tap on every variable running around would be more heftier that your script/program load.
If you want to include only static dependencies you can do it using my tool:
https://github.com/bedbad/pyimports
In particular you work around ast like this:
def get_imports(path):
imports = dict()
with open(path) as fh:
root = ast.parse(fh.read(), path)
for node in ast.iter_child_nodes(root):
if isinstance(node, ast.Import):
temp = imports
for n in node.names:
namelist = n.name.split('.')
if len(namelist) > 1:
for st in namelist:
temp[st] = dict()
temp = temp[st]
else:
temp[n.name] = dict()
elif isinstance(node, ast.ImportFrom):
temp = imports
namelist = node.module.split('.')
for n in namelist:
temp[n] = dict()
temp = temp[n]
for n in node.names:
temp[n.name] = dict()
else:
continue
return imports
use __name__ attribute
>>> import numpy
>>> x = numpy
>>> y = x.__name__
>>> y
'numpy'
Edit:
import numpy
arr = []
def a(strofwanted, library, varname):
global arr
arr.append([varname, library])
return exec(strofwanted)
x = a("numpy.array([1, 2])", "numpy", "x")
>>>x
[1,2]
>>>arr
[["x", "numpy"]]
