I don't know if this logic is correct,
I'm trying to import a Django view in 2 different views.
I have an import chain like this:
the
a.views import b.views
b.views import c.views
c.views import d.views
and
d.views import b.views
but when I reach the last step I get an ImportError.
If I put a comment in d.views avoiding the import of b.views, it works.
I'm new with Django, can somebody help me?
If I use in a.views and in d.views the syntax
from b.views import *
it works, but.. the code is not so readable.
If I use
from b.views import my_func
it doesn't work!
This is the error from django shell:
>>> import maps.views
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/Users/save/sites/myblog/maps/views.py", line 19, in <module>
from places.views import *
File "/Users/save/sites/myblog/places/views.py", line 22, in <module>
from posts.views import *
File "/Users/save/sites/myblog/posts/views.py", line 31, in <module>
from maps.views import render_map_geoloc
ImportError: cannot import name render_map_geoloc
Its because of cyclic dependency or circular reference.
b depends on c
c depends on d
d depends on b #which depends on c
Not sure for what purpose you are using. But you do explicit import to that function, and right above where its been used.
Looking at the error you are getting, it might be because of some dependency expected for d is coming from b so if you from b.views import *, it gets you that dependency. But if you import specific view (my_func), its missing that dependency.
Some more details you can find on SO answer thread - Django App Dependency Cycle
Related
This question already has answers here:
How to avoid circular imports in Python? [duplicate]
(3 answers)
Closed 2 years ago.
I am having the error below and I am not sure how to fix it. I know it has something to do with my imports but I am not sure what needs to be done in order to fix this issue.
Traceback (most recent call last):
File "WebOutput.py", line 1, in <module>
import DatabaseInteractor
File "/Users/yaminhimani/Desktop/tweetybird/DatabaseInteractor.py", line 3, in <module>
import WebOutput
File "/Users/yaminhimani/Desktop/tweetybird/WebOutput.py", line 4, in <module>
db = DatabaseInteractor.DatabaseInteractor()
AttributeError: partially initialized module 'DatabaseInteractor' has no attribute 'DatabaseInteractor' (most likely due to a circular import)
WebOutput.py file
import DatabaseInteractor
import nltk
db = DatabaseInteractor.DatabaseInteractor()
class WebOutput:
def __init__(self,text):
self.text= text
#self.hashtag = input("Enter Hashtag")
DataInteractor.py file
import mysql.connector
import Tweet
import WebOutput
import re
class DatabaseInteractor:
def __init__(self):
# connects to the mysql server
# config settings should be changed based on where you are trying to connect (they are currently set for my local sql server)
config = {
}
You are importing DatabaseInteractor in WebOutput, then you are importing WebOutput in DatabaseInteractor!! I suggest you to move something to another file, just import it in both for what you need or rearrange the code in some way you have to figure out not to need one each other!!
noob question series...
I am a new learner of python, recently want to create a small python application that can collect photos from flickr based on different search input. (eg: if i input "dog", it will download all dog images from flickr)
I did some research online and notice that flickr API might be the best way and the method flickr.photos.getSizes should be the one I need to use.
However, I have few stupid questions when coding:
I have applied my key and secret for flickr API, I just don't know what to do next with flickr.photos.getSizes in python to download photos. Like, how to call this method in python? (and I noticed required arguments for this method are keys and photo_id, how to get photo_ids based on search input "dog")
Then I followed a tutorial from https://github.com/alexis-mignon/python-flickr-api/wiki/Tutorial but when I imported flickr_api I got error message:
Could not load all modules
<class 'ImportError'> No module named 'objects'
Traceback (most recent call last):
File "D:/Agfa/Projects/Image/flickr.py", line 2, in <module>
import flickr_api
File "D:\Application\Anaconda3\lib\site-packages\flickr_api\__init__.py", line 32, in <module>
from auth import set_auth_handler
ImportError: cannot import name 'set_auth_handler'
Then I took a look at the _ init _.py:
try:
from objects import *
import objects
import upload as Upload
from upload import upload, replace
except Exception as e:
print "Could not load all modules"
print type(e), e
from auth import set_auth_handler
from method_call import enable_cache, disable_cache
from keys import set_keys
from _version import __version__
Seems like this library does not support python 3 but I don't know what to do. (I cannot install methond_call, keys, _version on my python 3) guess I will use flickrapi
Thank you so much for your time and again thanks in advance.
I think I finally got the proper way to use FlickrAPI:
there are many ways but I figured out 2:
def flickr_walk(keyward):
count = 0
photos = flickr.walk(text=keyward,
tag_mode='all',
tags=keyward,
extras='url_c',
per_page=100)
for photo in photos:
try:
url=photo.get('url_c')
urllib.request.urlretrieve(url, path+'\\' + str(count) +".jpg")
except Exception as e:
print('failed to download image')
flickr.walk uses Photos.search API, I can use the API directly as well:
def flickr_search(keyward):
obj = flickr.photos.search(text=keyward,
tags=keyward,
extras='url_c',
per_page=5)
for photo in obj:
url=photo.get('url_c')
photos = ET.dump(obj)
print (photos)
Remember to get the key and secret first:
api_key = 'xxxxxxxxxxxxxxxx'
api_secret = 'xxxxxxxxxxxxx'
flickr=flickrapi.FlickrAPI(api_key,api_secret,cache=True)
I dont have any clue on the why/how. If you want to use the flickr_api module with python3.5+, you need to fix the Imports, like I did below:
try:
from objects import *
import objects
import upload as Upload
from upload import upload, replace
except Exception as e:
#print "Could not load all modules"
print( type(e), e)
from .auth import set_auth_handler
from .method_call import enable_cache, disable_cache
from .keys import set_keys
from ._version import __version__
After this edit, it fails with another Import Error on:
>>> import flickr_api
<class 'SyntaxError'> invalid syntax (method_call.py, line 50)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/krysopath/.local/lib/python3.5/site-packages/flickr_api/__init__.py", line 32, in <module>
from .auth import set_auth_handler
File "/home/krysopath/.local/lib/python3.5/site-packages/flickr_api/auth.py", line 43, in <module>
import urlparse
ImportError: No module named 'urlparse'
So you can fix this by yourself, if you want to, by just walking along the Import Errors and adding a dot to convert them into absolute Imports, that dont fail.
I guess, if you want to use this modul you have to fix it first... and have an unknown return. So if you didnt already invested heavily, it might be more effective to use that other module.
I know this question has been asked countless times here, but I've been stuck with this problem for a long time and have not been able to find a solution online.
I have an import cycle, and here is the stack trace:
Traceback (most recent call last):
File "openldap_lookup.py", line 2, in <module>
import pure.directory_service.ds_lookup as dsl
File "/home/myname/purity/tools/pure/directory_service/ds_lookup.py", line 8, in <module>
import pure.authorization.auth as auth
File "/home/myname/purity/tools/pure/authorization/auth.py", line 16, in <module>
import auth_unix as auth_impl
File "/home/myname/purity/tools/pure/authorization/auth_unix.py", line 17, in <module>
import pure.directory_service.ad_lookup as ad_lookup
File "/home/myname/purity/tools/pure/directory_service/ad_lookup.py", line 1, in <module>
import pure.authorization.auth as auth
AttributeError: 'module' object has no attribute 'auth'
I import modules only; I avoid the from <module> import <class> and from <module> import <method>
I tried to reproduce the error locally, but python has no complaints. These are the local test files:
openldap_lookup.py
import ds_lookup
def openldap_foo():
print ds_lookup.ds_foo
print 'openldap_lookup importing ds_lookup'
ds_lookup.py
import auth as au
def ds_foo():
print au.auth_foo
print 'ds_lookup importing auth'
auth.py
import auth_unix
def auth_foo():
print auth_unix.auth_unix_foo
print 'auth importing auth_unix'
auth_unix.py
import ad_lookup
def auth_unix_foo():
print ad_lookup.ad_foo
print 'auth_unix importing ad_lookup'
ad_lookup.py
import auth as au
def ad_foo():
print au.auth_foo
print 'ad_lookup importing auth'
But python doesn't complain:
myname#myname-mbp:~/cycletest$ python openldap_lookup.py
ad_lookup importing auth
auth_unix importing ad_lookup
auth importing auth_unix
ds_lookup importing auth
openldap_lookup importing ds_lookup
myname#myname-mbp:~/cycletest$
I am not a python expert, but I understand that an import cycle is causing the error. But why doesn't the same error occur with the small test files? When is an import cycle legal in python and when is it not? What can I do to resolve this?
I would greatly appreciate any help from the python experts out there.
Since many are bound to ask, why do I have this cycle in the first place?
Well, openldap_lookup and ad_lookup both contain subclasses of a base class in ds_lookup. ds_lookup requires constants from auth. auth requires auth_unix as an implementation, and auth_unix in turn calls the implementations openldap_lookup and ad_lookup.
I would love to move the constants out from auth and remove the cycle, but this code is part of a large git repo where hundreds of files depend on the constants and methods in auth, and I would like to avoid having to refactor all of them if possible.
Actually, you're not just importing modules -- you're importing modules from packages, and your test case doesn't actually reflect this.
I think the problem is that in your first import of pure.authorization.auth, the interpreter is still building the pure.authorization module (it hasn't yet bound auth into pure.authorization, because it hasn't finished importing auth), so the second time it encounters this, it finds the pure.authorization module, but there is no global variable auth in it yet.
As far as breaking the cycle goes, does auth really need to import auth_unix right away, or could that be deferred until you really need an auth implementation?
I'm creating a simple flask app. I'm using blueprints to provide views and OpenID for login. I have faced the problem when I try to import created OpenID object to the file with the views interpreter throws an Import Error.
Traceback (most recent call last):
File "/.../ProgList/ProgList.py", line 11, in <module>
from views_admin import views as views_a
File "/.../ProgList/views_admin.py", line 4, in <module>
from ProgList import open_id
File "/.../ProgList/ProgList.py", line 11, in <module>
from views_admin import views as views_a
ImportError: cannot import name 'views'
ProgList.py
# importing VIEWS
from views import views
from views_admin import views as views_a
...
open_id = OpenID(app, 'temp_dir_path')
views_admin.py
from ProgList import open_id
...
#views.route("/login", methods=["GET", "POST"])
#open_id.loginhandler
def login():
I have been struggling this problem for hours and couldn't find an answer.
Thank you very much for help.
In ProgList, you import views_admin, in views_admin, you import ProgList. This cannot be resolved. The typical approach here is to outsource something to a third file which both can safely access without interfering with each other. From the looks of it, you might want to move open_id into a different file.
I've been scouring the internet for a solution and everything i've come across hasn't helped. So now i turn to you.
Traceback (most recent call last):
File "cardreader.py", line 9, in <module>
import ATRdb as ATR
File "/home/pi/Desktop/CardReader/ATRdb.py", line 4, in <module>
import cardreader
File "/home/pi/Desktop/CardReader/cardreader.py", line 113, in <module>
main()
File "/home/pi/Desktop/CardReader/cardreader.py", line 40, in main
getData(db)
File "/home/pi/Desktop/CardReader/cardreader.py", line 98, in getData
if ATR.checkPerms(db,track1):
AttributeError: 'module' object has no attribute 'checkPerms'
I have two files cardreader.py & ATRdb.py
---ATRdb.py has this setup
import sys
import MYSQLdb
import datetime
import cardreader
def checkPerms(db, securitycode):
try:
cursor = db.cursor()
cursor.execute("""SELECT permissions FROM atrsecurity.employee WHERE securitycode = %s""", (securitycode))
r = cursor.fetchone()
Permissions = r
if '3' in Permissions[0]:
return True
else:
return False
except Exception:
cardreader.main()
return False
---cardreader.py has this setup
import sys
import usb.core
import usb.util
import MYSQLdb
import ATRdb as ATR
def main():
db = MYSQLdb.connect(HOST,USER, PASS, DB)
print("Please swipe your card...")
getData(db)
main()
db.close()
def getData(db):
#
#lots of code to get card data
#
if ATR.checkPerms(db, track1):
print ("User has permission")
unlockDoor()
i get the error at the "If ATR.checkPerms():" part. Any help would be appreciated
(first python project)
Your problem is circular imports.
In cardreader, you do this:
import ATRdb as ATR
That starts importing ATRdb, but a few lines into the code, it hits this:
import cardreader
The exact sequence from here depends on whether cardreader.py is your main script or not, and on whether your top-level code that calls main is protected by an if __name__ == '__main__' guard (and assuming that top-level code is in cardreader rather than elsewhere). Rather than try to explain all the possibilities in detail (or wait for you to tell us which one matches your actual code), let's look at what we know is true based on the behavior:
In some way, you're calling main before finishing the import of ATRdb.
This means that, at this point, ATRdb has nothing in it but sys, MYSQLdb, and datetime (and a handful of special attributes that every module gets automatically). In particular, it hasn't gotten to the definition of checkPerms yet, so no such attribute exists in the module yet.
Of course eventually it's going to finish importing the rest of ATRdb, but at that point it's too late; you've already called main and it tried to call ATR.checkPerms and that failed.
While there are various complicated ways to make circular imports work (see the official FAQ for some), the easiest and cleanest solution is to just not do it. If ATRdb needs some functions that are in cardreader, you should probably factor those out into a third module, like cardutils, that both ATRdb and cardreader can import.