Answers for "importerror: cannot import name"

importerror: cannot import name

# Python ImportError: cannot import name error 
# is cause by either:  
# 1: The import module/class is inaccessible (not installed or ot reacheable by current PYTHONPATH)
# 	 Fix : Install module with pip or easy install or correct PYTHONPATH

# 2: You have created a circular dependancy such as:

# in foo.py
...
import bar
...

# in bar.py
...
import foo
...

# How to Fix it
# 1 - refactor your code (not always straitforward ...)
# 2 - Of course you should definitely avoid circular dependencies, 
#     but sometimes as a quick fix you can use some kind of lazy loading to defer imports

# In a method or function

def function_using_foo():
	import foo
    # now u can use foo here
    foo.baz()
    ...
    
def function_returning_foo():
	import foo
    # Hint: You can cache foo for more efficiency ...
    return foo  

# now u can use foo everywhere this way
function_returning_foo().baz()

importerror: cannot import name

# While you should definitely avoid circular dependencies,
# you can defer imports in python.
# for example:

import SomeModule

def someFunction(arg):
    from some.dependency import DependentClass
    
#this ( at least in some instances ) will circumvent the error.

importerror: cannot import name

import SomeModule

def someFunction(arg):
    from some.dependency import DependentClass

importerror: cannot import name

While you should definitely avoid circular dependencies, you can defer imports in python.

for example:

import SomeModule

def someFunction(arg):
    from some.dependency import DependentClass
this ( at least in some instances ) will circumvent the error.

importerror: cannot import name

This is a circular dependency. It can be solved without any structural modifications to the code. The problem occurs because in vector you demand that entity be made available for use immediately, and vice versa. The reason for this problem is that you asking to access the contents of the module before it is ready -- by using from x import y. This is essentially the same as

import x
y = x.y
del x
Python is able to detect circular dependencies and prevent the infinite loop of imports. Essentially all that happens is that an empty placeholder is created for the module (ie. it has no content). Once the circularly dependent modules are compiled it updates the imported module. This is works something like this.

a = module() # import a

# rest of module

a.update_contents(real_a)
For python to be able to work with circular dependencies you must use import x style only.

import x
class cls:
    def __init__(self):
        self.y = x.y
Since you are no longer referring to the contents of the module at the top level, python can compile the module without actually having to access the contents of the circular dependency. By top level I mean lines that will be executed during compilation as opposed to the contents of functions (eg. y = x.y). Static or class variables accessing the module contents will also cause problems.

importerror: cannot import name

Search your entire project/solution (generally ctrl-shift-f) for 'flask' or whatever the name import error is.
You may have it being imported twice and just need to remove one.

importerror: cannot import name

from django.conf.urls import include

importerror: cannot import name

This is a circular dependency. It can be solved without any structural modifications to the code. The problem occurs because in vector you demand that entity be made available for use immediately, and vice versa. The reason for this problem is that you asking to access the contents of the module before it is ready -- by using from x import y. This is essentially the same as

import x
y = x.y
del x
Python is able to detect circular dependencies and prevent the infinite loop of imports. Essentially all that happens is that an empty placeholder is created for the module (ie. it has no content). Once the circularly dependent modules are compiled it updates the imported module. This is works something like this.

a = module() # import a

# rest of module