I wrote functions that are applyRules(ch), processString(Oldstr) and named it lsystems.py
And I put
import lsystems
def main():
inst = applyRules("F")
print(inst)
main()
and saved it as mainfunctioni
However, when I try to run mainfunctioni, it says 'applyRules' is not defined.
Doesn't it work because I put import lsystems?
What should I do to work my mainfunctioni through lsystems?
You have to call it with module.function() format. So in this case, it should be called like as follows:
inst = lsystems.applyRules("F")
You have to access all the methods from your module with the same format. For processString(Oldstr), it should be similar.
test_string = lsystems.processString("Somestring")
When you import a module using import <module> syntax, you need to access the module's contents through its namespace, like so:
import lsystems
def main():
inst = lsystems.applyRules("F")
print(inst)
main()
Alternatively, you can directly import the function from the module:
from lsystems import applyRules
def main():
inst = applyRules("F")
print(inst)
main()
Related
I'm simply trying to import a function from another script. But despite import running successfully, the functions never enter my local environment.
The paths and files look like this:
project/__main__.py
project/script_a.py
from setup import script_b
x = ABC() # NameError: name 'ABC' is not defined
print(x)
project/setup/__init__.py
project/setup/script_b.py
def ABC():
return "ABC"
I've done this before and the documentation (officials and on here) is quite straightforward but I cannot grasp what I am failing to understand. Is the function running but never entering my environment?
I also tried using...
if __name__ == '__main__':
def ABC():
return "ABC"
...as script_b.
Import the functions inside the module:
from setup.script_b import ABC
Or call the function on the modules name like said in the comments
x = script_b.ABC()
Im trying to import files on Flask app in base of url route. I started to coding python few days ago so i havent idea if i doing it well. I write this on :
#app.route('/<file>')
def call(file):
__import__('controller.'+file)
hello = Example('Hello world')
return hello.msg
And i have other file called example.py into a controller folder that contains this:
class Example:
def __init__(self, msg):
self.msg = msg
So i start from terminal the app and i try to enter to localhost:5000/example.
Im trying to show in screen Hello world but give me the next error:
NameError: global name 'Example' is not defined
Thanks for all!
__import__ returns the newly imported module; names from that module are not added to your globals, so you need to get the Example class as an attribute from the returned module:
module = __import__('controller.'+file)
hello = module.Example('Hello world')
__import__ is rather low-level, you probably want to use importlib.import_module() instead:
import importlib
module = importlib.import_module('controller.'+file)
hello = module.Example('Hello world')
If you need to dynamically get the classname too, use getattr():
class_name = 'Example'
hello_class = getattr(module, class_name)
hello = hello_class('Hello world')
The Werkzeug package (used by Flask) offers a helpful functions here: werkzeug.utils.import_string() imports an object dynamically:
from werkzeug.utils import import_string
object_name = 'controller.{}:Example'.format(file)
hello_class = import_string(object_name)
This encapsulates the above process.
You'll need to be extremely careful with accepting names from web requests and using those as module names. Please do sanitise the file argument and only allow alphanumerics to prevent relative imports from being used.
You could use the werkzeug.utils.find_modules() function to limit the possible values for file here:
from werkzeug.utils import find_modules, import_string
module_name = 'controller.{}'.format(file)
if module_name not in set(find_modules('controller')):
abort(404) # no such module in the controller package
hello_class = import_string(module_name + ':Example')
I think you might not add the directory to the file, add the following code into the previous python program
# Add another directory
import sys
sys.path.insert(0, '/your_directory')
from Example import Example
There are two ways for you to do imports in Python:
import example
e = example.Example('hello world')
or
from example import Example
e = Example('hello world')
I'm using EasyGui to allow a user to select multiple options. Each option is a function which they can run if they select it. I'm trying to use dictionaries as suggested in other threads but I'm having trouble implementing it (Module object is not callable error). Is there something I'm missing?
from easygui import *
import emdtest1
import emdtest2
import emdtest3
EMDTestsDict = {"emdtest1":emdtest1,
"emdtest2":emdtest2,
"emdtest3":emdtest3}
def main():
test_list = UserSelect()
for i in range(len(test_list)):
if test_list[i] in EMDTestsDict.keys():
EMDTestsDict[test_list[i]]()
def UserSelect():
message = "Which EMD tests would you like to run?"
title = "EMD Test Selector"
tests = ["emdtest1",
"emdtest2",
"emdtest3"]
selected_master = multchoicebox(message, title, tests)
return selected_master
if __name__ == '__main__':
main()
You're putting modules into the dict, when you want to put functions in it. What you're doing is the equivalent of saying
import os
os()
Which, of course, makes no sense. If emdtest1, emdtest2, and emdtest3 are .py files with functions in them, you want:
from emdtest1 import function_name
Where function_name is the name of your function.
You need to import the functions rather than the module ... for example , if you have a file called emdtest1 with a defined function emdtest1, you'd use:
from emdtest1 import emdtest1
I have a string, say: abc.def.ghi.jkl.myfile.mymethod. How do I dynamically import mymethod?
Here is how I went about it:
def get_method_from_file(full_path):
if len(full_path) == 1:
return map(__import__,[full_path[0]])[0]
return getattr(get_method_from_file(full_path[:-1]),full_path[-1])
if __name__=='__main__':
print get_method_from_file('abc.def.ghi.jkl.myfile.mymethod'.split('.'))
I am wondering if the importing individual modules is required at all.
Edit: I am using Python version 2.6.5.
From Python 2.7 you can use the importlib.import_module() function. You can import a module and access an object defined within it with the following code:
from importlib import import_module
p, m = name.rsplit('.', 1)
mod = import_module(p)
met = getattr(mod, m)
met()
You don't need to import the individual modules. It is enough to import the module you want to import a name from and provide the fromlist argument:
def import_from(module, name):
module = __import__(module, fromlist=[name])
return getattr(module, name)
For your example abc.def.ghi.jkl.myfile.mymethod, call this function as
import_from("abc.def.ghi.jkl.myfile", "mymethod")
(Note that module-level functions are called functions in Python, not methods.)
For such a simple task, there is no advantage in using the importlib module.
For Python < 2.7 the builtin method __ import__ can be used:
__import__('abc.def.ghi.jkl.myfile.mymethod', fromlist=[''])
For Python >= 2.7 or 3.1 the convenient method importlib.import_module has been added. Just import your module like this:
importlib.import_module('abc.def.ghi.jkl.myfile.mymethod')
Update: Updated version according to comments (I must admit I didn't read the string to be imported till the end and I missed the fact that a method of a module should be imported and not a module itself):
Python < 2.7 :
mymethod = getattr(__import__("abc.def.ghi.jkl.myfile", fromlist=["mymethod"]))
Python >= 2.7:
mymethod = getattr(importlib.import_module("abc.def.ghi.jkl.myfile"), "mymethod")
from importlib import import_module
name = "file.py".strip('.py')
# if Path like : "path/python/file.py"
# use name.replaces("/",".")
imp = import_module(name)
# get Class From File.py
model = getattr(imp, "classNameImportFromFile")
NClass = model() # Class From file
It's unclear what you are trying to do to your local namespace. I assume you want just my_method as a local, typing output = my_method()?
# This is equivalent to "from a.b.myfile import my_method"
the_module = importlib.import_module("a.b.myfile")
same_module = __import__("a.b.myfile")
# import_module() and __input__() only return modules
my_method = getattr(the_module, "my_method")
# or, more concisely,
my_method = getattr(__import__("a.b.myfile"), "my_method")
output = my_method()
While you only add my_method to the local namespace, you do load the chain of modules. You can look at changes by watching the keys of sys.modules before and after the import. I hope this is clearer and more accurate than your other answers.
For completeness, this is how you add the whole chain.
# This is equivalent to "import a.b.myfile"
a = __import__("a.b.myfile")
also_a = importlib.import_module("a.b.myfile")
output = a.b.myfile.my_method()
# This is equivalent to "from a.b import myfile"
myfile = __import__("a.b.myfile", fromlist="a.b")
also_myfile = importlib.import_module("a.b.myfile", "a.b")
output = myfile.my_method()
And, finally, if you are using __import__() and have modified you search path after the program started, you may need to use __import__(normal args, globals=globals(), locals=locals()). The why is a complex discussion.
This website has a nice solution: load_class. I use it like this:
foo = load_class(package.subpackage.FooClass)()
type(foo) # returns FooClass
As requested, here is the code from the web link:
import importlib
def load_class(full_class_string):
"""
dynamically load a class from a string
"""
class_data = full_class_string.split(".")
module_path = ".".join(class_data[:-1])
class_str = class_data[-1]
module = importlib.import_module(module_path)
# Finally, we retrieve the Class
return getattr(module, class_str)
Use importlib (2.7+ only).
The way I tend to to this (as well as a number of other libraries, such as pylons and paste, if my memory serves me correctly) is to separate the module name from the function/attribute name by using a ':' between them. See the following example:
'abc.def.ghi.jkl.myfile:mymethod'
This makes the import_from(path) function below a little easier to use.
def import_from(path):
"""
Import an attribute, function or class from a module.
:attr path: A path descriptor in the form of 'pkg.module.submodule:attribute'
:type path: str
"""
path_parts = path.split(':')
if len(path_parts) < 2:
raise ImportError("path must be in the form of pkg.module.submodule:attribute")
module = __import__(path_parts[0], fromlist=path_parts[1])
return getattr(module, path_parts[1])
if __name__=='__main__':
func = import_from('a.b.c.d.myfile:mymethod')
func()
How about this :
def import_module(name):
mod = __import__(name)
for s in name.split('.')[1:]:
mod = getattr(mod, s)
return mod
I'm using Python 2.6.1 on Mac OS X.
I have two simple Python files (below), but when I run
python update_url.py
I get on the terminal:
Traceback (most recent call last):
File "update_urls.py", line 7, in <module>
main()
File "update_urls.py", line 4, in main
db = SqliteDBzz()
NameError: global name 'SqliteDBzz' is not defined
I tried renaming the files and classes differently, which is why there's x and z on the ends. ;)
File sqlitedbx.py
class SqliteDBzz:
connection = ''
curser = ''
def connect(self):
print "foo"
def find_or_create(self, table, column, value):
print "baar"
File update_url.py
import sqlitedbx
def main():
db = SqliteDBzz()
db.connect
if __name__ == "__main__":
main()
You need to do:
import sqlitedbx
def main():
db = sqlitedbx.SqliteDBzz()
db.connect()
if __name__ == "__main__":
main()
try
from sqlitedbx import SqliteDBzz
Importing the namespace is somewhat cleaner. Imagine you have two different modules you import, both of them with the same method/class. Some bad stuff might happen. I'd dare say it is usually good practice to use:
import module
over
from module import function/class
That's How Python works.
Try this :
from sqlitedbx import SqliteDBzz
Such that you can directly use the name without the enclosing module.Or just import the module and prepend 'sqlitedbx.' to your function,class etc