Develop Reference

ImportError attempted relative import with no known parent

Based on some answers I try to be more specific.
I want to import the print and the models AND code in my main.py
I know the question gets asked a lot, but still I could not figure out whats wrong with my code!
I have a project directory like this
-project
--__init__py
--main.py
--print.py
--requests
--__init__.py
--models.py
--code.py
i want to import from print.py and * from requests
Therefore I tried to add these lines in main.py
from . import print
#or
import print
#for requests I tried
import os.path
import sys
sys.path.append('./requests')
from requests import *
all of those lines cause the same ImportError attempted relative import with no known parent ,
using Python 39
anyone an idea where the problem is?
I am very confused that this seems not to work, was it possible in older versions?

You should definitely not be doing anything with sys.path. If you are using a correct Python package structure, the import system should handle everything like this.
From the directory structure you described, project would be the name of your package. So when using your package in some external code you would do
import package
or to use a submodule/subpackage
import project.print
import project.requests
and so on.
For modules inside the package you can use relative imports. When you write
i want to import from print.py and * from requests Therefore I tried
it's not clear from where you want to import them, because this is important for relative imports.
For example, in project/main.py to import the print module you could use:
from . import print
But if it's from project/requests/code.py you would use
from .. import print
As an aside, "print" is probably not a good name for a module, since if you import the print module it will shadow the print() built-in function.

Your main file should be outside the 'project'-directory to use that as a package.
Then, from your main file, you can import using from project.print import ....
Within the project-package, relative imports are possible.

How do I properly run a separate python script from main python file?

I am trying to make my python script more modular -- it works properly when everything is in just one lengthy .py file, but I want to use the main python file to call other files to streamline the flow and make upgrades easier.
I'm struggling with package imports. One package I'm using is os, which I import in the main file:
import os
import pandas as pd
import numpy as np
from code_module_1 import *
if __name__ == '__main__':
code_module_1()
I also import it at the top of the python file that is called, code_module_1.py:
import os
import glob
import pandas as pd
import numpy as np
def function_called_from_main():
for root, dirs, files in os.walk('...file_path'):
etc.
When I do this, I receive an error saying the name 'os' is not defined, which I've taken to mean that the package isn't being imported in code_module_1.
I've attempted to fix this by placing the lines of code that import packages inside of the function that I'm calling from the main script, but I still run into the same error. Where should I be importing packages, and how do I make sure that other python files that are called have the packages that they need to run?

With the following line
from code_module_1 import *
you import everything defined in the module. So basically, all function definitions are available.
Next, you can't execute a module. You can only execute a function or a statement. Thus, the following line
if __name__ == '__main__':
code_module_1()
should be something like this:
if __name__ == '__main__':
function_called_from_main()
where you execute the function function_called_from_main that was previously imported.

Importing python modules from another directory

I am trying to import files (python files) from another directory but it is not working as I have tried.
/pythonproject
.main.py
.__init__.py
->folder1
->.file1.py
->.file2.py
->.__init__.py
->folder2
->.functions.py
->.globals.py
->.__init__.py
I am trying to import functions.py inside of my file2.py.
I have tried
from functions import *
import functions
#file2.py
sys.path.insert(0, '/pythonproject')
import functions

I think your friend for this case is sys.path.append.

As discovered the problem is that you are importing the file, but when you went to use a function in the file you couldn't
One solution is:
import functions
functions.NameOfFunctionHere()

Writing a Python module to import other modules

I want to write a Python module that automatically imports all the good stuff for me (about 50 other modules) so I don't have to copy and past them every time I start a new script. I attempted this by defining the following method in my module, soon to realize when I import my module and call this method, the imports take place locally.
def auto_import():
import os
import sys
# plus 50 other modules...
How can I accomplish this automation using modular programming? (I am using Python 3.6. on Ubuntu.)

You don't need a function to do that, you can simply make a file like commonimports.py which looks like this:
import os
import numpy as np
import sys
#and so on...
And add this import statement in other files
from commonimports import *
And you'll have all the modules ready to use within that namespace

Just make the name of your imported modules global:
def auto_import():
import os
import sys
global os, sys

This is not necessary to use this method if you def auto_import() then every time you have to use a autoimport function whenever you want to use those module.

Using Numpy from keyword.py

I want to use NumPy in a Python script that uses pandas to process an Excel file. However, one of my constraints is that my file must be named keyword.py, which causes an import error. The import error is traced back to a line from keyword import iskeyword as _iskeyword in C:\Python27\lib\collections.py, which I assume causes an error because my own keyword.py is overriding the default keyword module. Is there any way to avoid this collision?

Not pretty, but a keyword.py of
if True:
import imp, sys
keyword_loc = imp.find_module("keyword", sys.path[1:])[1]
imp.load_source("keyword", keyword_loc)
import collections
print(collections.Counter)
fails with an AttributeError if we replace True with False, but gives me
(2.7) dsm#notebook:~/coding/kw$ python keyword.py
<class 'collections.Counter'>
as is. This works by finding out where the original keyword library is and manually importing it. After this, any following attempts to import keyword will see that it's already there.

For working with a single script, you can remove the current directory from the import search path. That might be sufficient for working on your TopCoder problem, but I wouldn't recommend it as a long-term solution. (Long-term: don't use file names that mirror the standard library.)
If the following script is called keyword.py, it can be run and the import of collections will not trigger an error.
# keyword.py
# Remove the current directory from the import search path
# This is a hack, but it will be sufficient for working with a
# single script that doesn't import any other modules from the
# current directory.
import sys
sys.path = sys.path[1:]
import collections
print(collections)