My friend asked me to build a function that can execute code in a for loop so, I was doing that and I was using exec in the same file I was declaring a variable name, now when I access name from exec, it says NameError: name 'name' is not defined
This thing is in multiple files, one that runs everything, second that includes all functions and one that calls all functions
I have tried to define variables inside exec and sure, it works.
I have tried Accessing variables in functions.py(File that contains every function) file and it works too.
I have tried merging functions.py and test.py(the file that's using exec) and then running it directly through python and it worked
My functions.py file
def forloop(current, maximum, code):
for x in range(current, maximum):
exec(str(code), globals())
My 'test.py'(It's the one where I call functions)
from functions import *
name = 'Ameer'
forloop(1,3,"""
echo(name)
""")
And, I am running it all through another exec in my 'runner.py'
from functions import *
file = open('test.py', "r+")
content = file.read()
exec(content)
Now, it's giving me an error saying NameError: name 'name' is not defined when it is defined. Please can you guys help me with this issue
You need to use the variables from the place where forloop is called.
import inspect
def forloop(current, maximum, code):
frame = inspect.currentframe().f_back
for x in range(current, maximum):
exec(str(code), frame.f_globals, frame.f_locals)
Related
This is partially linked with my last question. I imported an object called current_user. I pass it in 2 variables from file 1 called guy.py, the variables are log_name and log_pass. These 2 variables are inputs from 2 entries and they're global. I made a function to import these global variables along with every other global that I have in gui.py. I'm still confused as to why the global variables are still being undefined.
This is the function which I use to import the object current_user:
def objects():
global log_name,log_pass
current_user = User(log_name,log_pass,score=0)
return current_user
And this is the function I tried using to import my global variables:
def global_vars():
global main_window,reg_window,name_entry,pass_entry,log_name_entry,log_pass_entry,log_name,log_pass,c,conn,query,data
The error I get is this:
current_user = User(log_name,log_pass,score=0)
NameError: name 'log_name' is not defined
as I understand you have to .py files: one is called guy.py the other I will call test.py:
so if you want to import values from guy.py to test.py. First define variables in guy.py like so:
log_name = yourvalue
log_pass = yourvalue
then go to test.py (it has to be in the same directory (to make it simple)) and import:
from guy import log_name, log_pass
now you can use these values in test.py and whenever you change the value in guy.py it will be changed in test.py. Also there is no need to make values global (for this case I think)
I'm making a small game and wanted a settings page function that's in a seperate .py file to keep things more clean and easily editable. I have a global variable called textSpeed (which I use the global keyword to use properly in the function) which I change in this runSettings function, but when I print the variable back in my main file it hasn't changed.
The code in the main file (main.py)
from settings import runSettings
textSpeed = "not set"
runSettings()
print(textSpeed)
The code from the settings fuction file (settings.py)
def runSettings():
global textSpeed
textSpeed = input("select text speed. ")
print(textSpeed)
return textSpeed
textSpeed is a local variable - local to the main module.
You need to reference the variable from settings.
import settings
settings.textSpeed = "not set"
runSettings()
print(settings.textSpeed)
To avoid circular import, I advise you to create a third file if you wish to keep it this way. Let's call it varSpeed.py with the following code:
global textSpeed
textSpeed = "not set"
Then you can import varSpeed from both other files have access to that variable without the circular issue.
The runSettings function already retuns the value it sets as well. Instead of messing with mixing namespaces and importing global variables, just use the returned value in main.py:
textSpeed = runSettings()
the problem is that you are trying to change a variable from a different file, while you have not imported the file. I think the easiest way to handle this is to use a class variable like this:
Main file:
from class_file import MyClass
MyClass.run_settings()
print(MyClass.text_speed)
Settings file:
class MyClass:
text_speed = 'n/a'
#staticmethod
def run_settings():
MyClass.text_speed = input("Select text speed: ")
return MyClass.text_speed
I'm writing a wrapper or pipeline to create a tfrecords dataset to which I would like to supply a function to apply to the dataset.
I would like to make it possible for the user to inject a function defined in another python file which is called in my script to transform the data.
Why? The only thing the user has to do is write the function which brings his data into the right format, then the existing code does the rest.
I'm aware of the fact that I could have the user write the function in the same file and call it, or to have an import statement etc.
So as a minimal example, I would like to have file y.py
def main(argv):
# Parse args etc, let's assume it is there.
dataset = tf.data.TFRecordDataset(args.filename)
dataset = dataset.map(args.function)
# Continue with doing stuff that is independent from actual content
So what I'd like to be able to do is something like this
python y.py --func x.py my_func
And use the function defined in x.py my_func in dataset.map(...)
Is there a way to do this in python and if yes, which is the best way to do it?
Pass the name of the file as an argument to your script (and function name)
Read the file into a string, possibly extracting the given function
use Python exec() to execute the code
An example:
file = "def fun(*args): \n return args"
func = "fun(1,2,3)"
def execute(func, file):
program = file + "\nresult = " + func
local = {}
exec(program, local)
return local['result']
r = execute(func, file)
print(r)
Similar to here however we must use locals() as we are not calling exec in global scope.
Note: the use of exec is somewhat dangerous, you should be sure that the function is safe - if you are using it then its fine!
Hope this helps.
Ok so I have composed the answer myself now using the information from comments and this answer.
import importlib, inspect, sys, os
# path is given path to file, funcion_name is name of function and args are the function arguments
# Create package and module name from path
package = os.path.dirname(path).replace(os.path.sep,'.')
module_name = os.path.basename(path).split('.')[0]
# Import module and get members
module = importlib.import_module(module_name, package)
members = inspect.getmembers(module)
# Find matching function
function = [t[1] for t in members if t[0] == function_name][0]
function(args)
This exactly solves the question, since I get a callable function object which I can call, pass around, use it as a normal function.
Assume, I have created an python file (FirstFile.py) name which contains many functions and other things. One of the function is this (of course, it is simplified):
def func(string):
assert eval(string)
Besides, I have created an python file which imports func() from the file mentioned above. Then this second python file try to execute following process:
from FirstFile import func
amk = 1
func("amk == 1")
When variable "amk" is in the first file, no problem reveals. However, when variable "amk" is in the second file, which is illustrated here, an error reveals:
NameError: name 'amk' is not defined
Would you like to please help me solve this problem?
by default eval executes in the current local/global scope, if you want to specify a different environment you can do something like:
eval("x == 1", {"x":1})
so your function could take an optional environ argument:
def func(string, environ=None):
assert eval(string, environ)
then you can call the function from the other module passing locals() as the environment:
from FirstFile import func
amk = 1
func("amk == 1", locals())
As a side note I'd recommend against evaluating arbitrary code especially if it is coming from another source / module as it could accidentally contain harmful code.
I have a problem with including a function from another file to main executable script. I have too many functions and my main script became too long and hard to manage. So i've decided to move every function to separate file and than attach/include it. I've read nearly any relative post here to resolve my problem but no luck. Let's see:
main_script.py
==================
from folder.another_file import f_fromanotherfile
class my_data:
MDList=[]
work=my_data()
def afunction():
f_fromanotherfile()
return
and
another_file.py
=====================
#In this file i've put just function code
def f_fromanotherfile():
a=[1,2,3,4]
work.MDList=a
return
And this is the error:
line 11, in f_fromanotherfile
work.MDList=a
NameError: global name 'work' is not defined
Help me please
The scope of 'work' is its module, main_script.py, so you cannot access it from another module. Make 'work' an argument of f_fromanotherfile instead:
In another_file.py:
def f_fromanotherfile(work):
# function body stays the same
In main_module.py:
def afunction():
f_fromanotherfile(work)
because in another_file.py
#In this file i've put just function code
def f_fromanotherfile():
a=[1,2,3,4]
work.MDList=a
return
work is not a global variable.And then doing assignment to it can't work.
u should change ur code to: another_file.py
#In this file i've put just function code
def f_fromanotherfile():
global work
a=[1,2,3,4]
work.MDList=a
return
with the global keyword u can say the variable in so-called global scope and do ur assignment.
PS:kind of like the keyword extern in C?