I have a strange error using the built in webserver in Django (haven't tested against Apache as I'm in active development). I have a url pattern that works for short url parameters (e.g. Chalk%20Hill), but locks up python on this one
http://localhost:8000/chargeback/checkDuplicateProject/Bexar%20Street%20Phase%20IV%20Brigham%20Ln%20to%20Myrtle%20St
The get request just says pending, and never returns, and I have to force quit python to get the server to function again. What am I doing wrong?
EDIT:
In continuing testing, it's strange, if I just enter the url, it returns the correct json response. Then it locks python. While I'm in the website, though, it never returns, and locks python.
urls:
url(r'^chargeback/checkDuplicateProject/(?P<aProjectName>(\w+)((\s)?(-)?(\w+)?)*)/$', 'chargeback.views.isProjectDuplicate'),
views:
def isProjectDuplicate(request, aProjectName):
#count the number of matching project names
p = Project.objects.filter(projectName__exact = aProjectName).count()
#if > 0, the project is a duplicate
if p > 0:
return HttpResponse('{"results":["Duplicate"]}', mimetype='application/json')
else:
return HttpResponse('{"results":["Not Duplicate"]}', mimetype='application/json')
Model:
class Project(models.Model):
projectName = models.TextField('project name')
department = models.ForeignKey('Department')
def __unicode__(self):
return self.projectName
The accepted answer is spot on about the regex, but since we're discussing optimization, I thought I should note that the code for checking whether a project exists could be modified to generate a much quicker query, especially in other contexts where you could be counting millions of rows needlessly. Call this 'best practices' advice, if you will.
p = Project.objects.filter(projectName__exact = aProjectName).count()
if p > 0:
could instead be
if Project.objects.filter(project_name__iexact=aProjectName).exists():
for two reasons.
First, you're not using p for anything so there's no need to store it as a variable as it increases readability and p is an obscure variable name and the best code is no code at all.
Secondly, this way we only ask for a single row instead of saving the results to the queryset cache. Please see the official Queryset API docs, a related question on Stack Overflow and the discussion about the latter on the django-developers group.
Additionally, it is customary in python (and Django, naturally) to name your fields lower_cased_separated_by_underscores. Please see more about this on the Python Style Guide (PEP 8).
Since you are going to check whether aProjectName already exists in the database, there's no need for you to make the regex so complicated.
I suggest you simplify the regex to
url(r'^chargeback/checkDuplicateProject/(?P<aProjectName>[\w+\s-]*)/$', 'chargeback.views.isProjectDuplicate'),
For a further explanation, see the question url regex keeps django busy/crashing on the django-users group.
Related
I want to get the assignment title of each assignment posted by the teacher in a specific course in Google Classroom. Can someone help me with this? When I try the API explorer on the official website, it returns the correct result but it doesn't work with my python file.
service = build('classroom', 'v1', credentials=creds)
# Call the Classroom API
results = service.courses().courseWork().get(courseId).execute()
courses = results.get('courses')
if not courses:
print('No courses found.')
else:
print('Courses:')
for course in courses:
print(course)
While you already accepted an answer, I think other people with your same problem might not be able to solved their issue based on that. Therefore, I'm posting an answer too.
Use correct parameters for "get" method:
You didn't specify which specific problem you had / what error were you getting (you just said it doesn't work), but the code you shared is not correct:
If you want to use courses.courseWork.get, you have to provide at least two parameters, for courseId and for id (referred to the assignment id), so it should be like this:
service.courses().courseWork().get(courseId=courseId, id=courseWorkId).execute()
Use "list" instead of "get":
But since you want to get the assignment titles of all the assignments in the course (and not for a single assignment), you should be using courses.courseWork.list instead. Your code should be something like this (where title is the title of each assignment):
courseWorkList = service.courses().courseWork().list(courseId=courseId).execute()
for courseWork in courseWorkList["courseWork"]:
title = courseWork["title"]
print(title)
And if the number of assignments is very large, you might need to use pageToken and nextPageToken, and call this method in a loop.
Use appropriate scopes:
If you're using list, you need to specify any of these scopes. Otherwise, you are not authorized to access this resource:
https://www.googleapis.com/auth/classroom.coursework.students.readonlyhttps://www.googleapis.com/auth/classroom.coursework.me.readonlyhttps://www.googleapis.com/auth/classroom.coursework.studentshttps://www.googleapis.com/auth/classroom.coursework.me
Reference:
get(courseId=None, id=*, x__xgafv=None)
list(courseId=None, orderBy=None, pageSize=None, courseWorkStates=None, pageToken=None, x__xgafv=None)
In order to access the coursework, you have to edit the predefined SCOPE in the sample code provided (and also delete the token.pickle file).
Check this, for a better understanding.
It appears that the quote() and unquote() methods inside django.contrib.admin.utils do not effectively handle underscores in primary keys. Specifically, I have some string-type primary keys that look like cus_C2xVQnht and when I use the django admin interface to edit them via the small pencil icon, the popup window will display an error like Customer with ID "cusÂxVQnht" doesn't exist. Perhaps it was deleted? (it is converting the C2 to the codepoint 00C2, aka Â. This is true for other valid codepoints as well (00C7, 00C6, 001B, etc)
If I manually go to the customers model and find the ID, I can pull it up and edit it just fine, but it seems the URL encoding doesn't work right when the primary key has an underscore in it.
After quite a lot of digging I managed to find these two functions buried deep inside django.contrib.admin.utils:
def quote(s):
"""
Ensure that primary key values do not confuse the admin URLs by escaping
any '/', '_' and ':' and similarly problematic characters.
Similar to urllib.parse.quote(), except that the quoting is slightly
different so that it doesn't get automatically unquoted by the Web browser.
"""
if not isinstance(s, str):
return s
res = list(s)
for i in range(len(res)):
c = res[i]
if c in """:/_#?;#&=+$,"[]<>%\n\\""":
res[i] = '_%02X' % ord(c)
return ''.join(res)
def unquote(s):
"""Undo the effects of quote(). Based heavily on urllib.parse.unquote()."""
mychr = chr
myatoi = int
list = s.split('_')
res = [list[0]]
myappend = res.append
del list[0]
for item in list:
if item[1:2]:
try:
myappend(mychr(myatoi(item[:2], 16)) + item[2:])
except ValueError:
myappend('_' + item)
else:
myappend('_' + item)
return "".join(res)
They appear to be called somewhere in the admin template rendering process, but I couldn't figure out where/how often/all the locations, so I decided to do a quick monkey patch to decide if it was worth pursuing as a solution: I changed all the underscores in quote() and unquote() except for the one in the list of problem characters in quote to dots...for example:
'_%02X' in quote()becomes '.%02X'
split('_') in unquote() becomes split('.')
myappend('_' + item) in unquote() becomes myappend('.' + item)
Upon doing this, the admin works correctly and it appears that the links attached to the edit icons on related fields are to the correct model instances, so I can edit them by clicking the pencil icons and don't get the error message noted above.
All that said, I can't seem to find a way to safely override these two methods. I really would rather not change the primary keys to eliminate the underscores because there are a lot of linked models in my database and it just seems like it will become a huge pain. This fix seems much easier and more reliable, and given that it worked properly on previous versions of Django I don't see how it's a bad idea to implement.
So, how can I override those methods? Or, as a related question, is there something I can do in the __str__ methods of my models to alleviate this problem? I'd do that much sooner than start writing custom classes that override Django admin internals. If there is no other solution, I would need some help in properly restructuring my database to adjust the primary keys, but I can say that these keys work perfectly on the "old" site I'm working on, which runs Django 1.11.6 and Python 2.7.9 (vs the current Django 2.1.1 and Python 3.6.5)
Please let me know if I can provide any more info. Thank you!!
This is fixed in django 2.2. See https://github.com/django/django/commit/e4df8e6dc021fa472fa77f9b835db74810184748
I'm trying to figure out if I'm following a user from which the streaming API just received a tweet. If I don't, then I want to follow him.
I've got something like:
def checkFollow(status):
relationship = api.lookup_friendships("Privacy_Watch_",status.user.id_str)
From there, how do I check if I follow this user already?
The lookup_friendships method will return everyone you follow each time you call it, in blocks of 100 users. Provided you follow a lot of people, that will be highly inefficient and consume a lot of requests.
You can use instead the show_friendship method, it will return a JSON containing information about your relationship with the id provided.
I cannot test it right now, but the following code should do what you want:
def checkFollow(status):
relation = api.show_friendship(source_screen_name=your_user_name, target_screen_name=status.user.id_str)
if relation.target.following: #I'm not sure if it should be "target" or "source" here
return True
return False
I'm pretty new to python, and currently playing with the zeroconf library.
when I try to register a service on the network, I'm seeing this in the function definition:
def register_service(self, info, ttl=_DNS_TTL):
"""Registers service information to the network with a default TTL
of 60 seconds. Zeroconf will then respond to requests for
information for that service. The name of the service may be
changed if needed to make it unique on the network."""
self.check_service(info)
self.services[info.name.lower()] = info
if info.type in self.servicetypes:
self.servicetypes[info.type] += 1
else:
self.servicetypes[info.type] = 1
now = current_time_millis()
next_time = now
i = 0
while i < 3:
if now < next_time:
self.wait(next_time - now)
now = current_time_millis()
continue
out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA)
out.add_answer_at_time(DNSPointer(info.type, _TYPE_PTR,
_CLASS_IN, ttl, info.name), 0)
out.add_answer_at_time(DNSService(info.name, _TYPE_SRV,
_CLASS_IN, ttl, info.priority, info.weight, info.port,
info.server), 0)
out.add_answer_at_time(DNSText(info.name, _TYPE_TXT, _CLASS_IN,
ttl, info.text), 0)
if info.address:
out.add_answer_at_time(DNSAddress(info.server, _TYPE_A,
_CLASS_IN, ttl, info.address), 0)
self.send(out)
i += 1
next_time += _REGISTER_TIME
Anyone know what type info is meant to be?
EDIT
Thanks for providing the answer that it's a ServiceInfo class. Besides the fact that the docstring provides this answer when one goes searching for it. I'm still unclear on:
the process expert python programmers follow when encountering this sort of situation - what steps to take to find the data type for info say when docstring wasn't available?
how does python interpreter know info is of ServiceInfo class when we don't specify the class type as part of the input param for register_service? How does it know info.type is a valid property, and say info.my_property isn't?
It is an instance of ServiceInfo class.
It can be deduced from reading the code and docstrings. register_service invokes check_service function which, I quote, "checks the network for a unique service name, modifying the ServiceInfo passed in if it is not unique".
It looks like it should be a ServiceInfo. Found in the examples of the repository:
https://github.com/jstasiak/python-zeroconf/blob/master/examples/registration.py
Edit
I'm not really sure what to say besides "any way I have to". In practice I can't really remember a time when the contract of the interface wasn't made perfectly clear, because that's just part of using Python. Documentation is more a requirement for this reason.
The short answer is, "it doesn't". Python uses the concept of "duck typing" in which any object that supports the necessary operations of the contract is valid. You could have given it any value that has all the properties the code uses and it wouldn't know the difference. So, per part 1, worst case you just have to trace every use of the object back as far as it is passed around and provide an object that meets all the requirements, and if you miss a piece, you'll get a runtime error for any code path that uses it.
My preference is for static typing as well. Largely I think documentation and unit tests just become "harder requirements" when working with dynamic typing since the compiler can't do any of that work for you.
I have a Django app that searches for data from a model Classified and displays them using simple querysets based on the input term. This works perfectly and I've got no complains with this method.
However, if someone enters a term that returns no data, I would like to provide an option with alternate/suggested search.
Eg: Someone searches 'Ambulance Services' which doesn't return data. I'd like to suggest 'Ambulance' or 'Services' as alternate search options which may return data from the model depending on the data present in the model.
I Googled suggested search in django and it gave me options of Haystack/elastic search, etc which I'm not sure are really required since the search is across just one model.
Note: SO tells me that my question may be closed as it is subjective. If thats the case, please suggest where I can move it to. Thank you!
This is just an idea, but might work for you:
The user enters the search data: "Ambulance Services"
If the query inside the view returns nothing, redirect to the same view using your selected alternative search data, lets say "Ambulance", and a flag value thats saids the view you're preforming a suggested search.
You must have two things in consideration:
What if the alternate search don't returns anything either? You have to set a recursion limit here.
How I'm going to select the data of the alternate search? Well, thats another question about a completly different topic.
This is this idea in code:
def search(request, data, alternate=False, recursion_level=3):
result = Classified.objects.filter(some_filed=data)
if 0 == result.count() and 0 != recursion_level: # Conditions needed for perform alternate search.
new_data = select_new_data(data) # The logic inside this function is up to you.
r_level = recursion_level - 1 # Decreas recursion level.
return redirect('search', alternate=True, recursion_level=r_level) # Redirecting using view name, you can use others
# forms of redirection see link below for visit
# the Djando redirect API doc.
else:
return_data = {}
if alternate:
# You can use this flag in order to reflect
# to the user you have performed an alternate search.
# Example:
return_data["alternate"] = True
# Build your return data.
# and render.
#return render_to_template()
Django redirect doc: redirect
Haystack is, indeed, a great option, here you will find how to give 'spelling suggestions', you can see an example in this OS question/answer
No matter you have only one model, this tool is really great, simple to install /set up/use, and very flexible.
Perhaps this helps as well.