if you encounter this error:
ImportError: Cannot import name whatever
with a python file called "whatever",
then this may be cause by the following issues:	1. file "whatever" is not in the same folder as the current file.	this means that you need to place file "whatever" inside the same file that gave you the import error. 2. library/module "whatever" is not installed.	if "whatever" is a third-party library/module, then you need to install the library/module. This is usually done with "pip install whatever", but exceptions do exist that the command is not the proper command to install "whatever" 3. if this file is in another folder, but you don't want to move it.	in this case, you should add this at the top of your file:	import sys	sys.path.append('path/to/file/whatever.py') replace 'path/to/file' with the proper directory of "whatever.py" 4. you forgot to create "whatever.py"!	well... just remember to do that before importing.
This does not include all of the possibilities. Hope this helped :D

# 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.

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.

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

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.

# 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()

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.

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