I am trying to build an accounting database using flask as the front end. The main page is the ledger, with nine columns "date" "description" "debit" "credit" "amount" "account" "reference" "journal" and "year", I need to be able to query each and some times two at once, there are over 8000 entries, and growing. My code so far displays all the rows, 200 at a time with pagination, I have read "pep 8" which talks about readable code, I have read this multiple parameters and this multiple parameters and like the idea of using
request.args.get
But I need to display all the rows until I query, I have also looked at this nested ifs and I thought perhaps I could use a function for each query and "If" out side of the view function and then call each in the view function, but I am not sure how to. Or I could have a view function for each query. But I am not sure how that would work, here is my code so far,
#bp.route('/books', methods=['GET', 'POST'])
#bp.route('/books/<int:page_num>', methods=['GET', 'POST'])
#bp.route('/books/<int:page_num>/<int:id>', methods=['GET', 'POST'])
#bp.route('/books/<int:page_num>/<int:id>/<ref>', methods=['GET', 'POST'])
#login_required
def books(page_num, id=None, ref=None):
if ref is not None:
books = Book.query.order_by(Book.date.desc()).filter(Book.REF==ref).paginate(per_page=100, page=page_num, error_out=True)
else:
books = Book.query.order_by(Book.date.desc()).paginate(per_page=100, page=page_num, error_out=True)
if id is not None:
obj = Book.query.get(id) or Book()
form = AddBookForm(request.form, obj=obj)
if form.validate_on_submit():
form.populate_obj(obj)
db.session.add(obj)
db.session.commit()
return redirect(url_for('books.books'))
else:
form = AddBookForm()
if form.validate_on_submit():
obj = Book(id=form.id.data, date=form.date.data, description=form.description.data, debit=form.debit.data,\
credit=form.credit.data, montant=form.montant.data, AUX=form.AUX.data, TP=form.TP.data,\
REF=form.REF.data, JN=form.JN.data, PID=form.PID.data, CT=form.CT.data)
db.session.add(obj)
db.session.commit()
return redirect(url_for('books.books', page_num=1))
return render_template('books/books.html', title='Books', books=books, form=form)
With this code there are no error messages, this is a question asking for advice on how to keep my code as readable and as simple as possible and be able to query nine columns of the database whilst displaying all the rows queried and all the rows when no query is activated
All help is greatly appreciated. Paul
I am running this on debian 10 with python 3.7
Edit: I am used to working with Libre Office Base
My question is How do I search one or two columns at a time in My database where I have nine columns out of twelve that I want to be able to search, I want to be able to search one or more at a time, example: column "reference" labels a document reference like "A32", and "account" by a the name of the supplier "FILCUI", possibly both at the same time. I have carried out more research and found that most people advocate a "fulltext" search engine such as "Elastic or Whoosh", But in my case I feel if I search "A32" ( a document number) I will get anything in the model of 12 columns with A 1 2. I have looked at Flask Tutorial 101 search Whoosh all very good tutorials, by excellent people, I thought about trying to use SQLAlchemy as a way, but in the first "Flask Tutorial" he says
but given the fact that SQLAlchemy does not support this functionality,
I thought that this SQLAlchemy-Intergrations will not work either.
So therefor is there a way to "search" "query" "filter" multiple different columns of a model with possibly a form for each search without ending up with a "sack of knots" like code impossible to read or test? I would like to stick to SQLAlchemy if possible
I need just a little pointer in the right direction or a simple personal opinion that I can test.
Warm regards.
EDIT:
I have not answered my question but I have advanced, I can query one row at a time and display all the results on the one page, with out a single "if" statement, i think my code is clear and readable (?) I divided each query into its own view function returning to the same main page, each function has its own submitt button. This has enabled me to render the same page. here is my routes code.
#bp.route('/search_aux', methods=['GET', 'POST'])
#login_required
def search_aux():
page_num = request.args.get('page_num', default = 1, type = int)
books = Book.query.order_by(Book.date.desc()).paginate(per_page=100, page=page_num, error_out=True)
add_form = AddBookForm()
aux_form = SearchAuxForm()
date_form = SearchDateForm()
debit_form = SearchDebitForm()
credit_form = SearchCreditForm()
montant_form = SearchMontantForm()
jn_form = SearchJNForm()
pid_form = SearchPIDForm()
ref_form = SearchREForm()
tp_form = SearchTPForm()
ct_form = SearchCTForm()
des_form = SearchDescriptionForm()
if request.method == 'POST':
aux = aux_form.selectaux.data
books = Book.query.order_by(Book.date.desc()).filter(Book.AUX == str(aux)).paginate(per_page=100, page=page_num, error_out=True)
return render_template('books/books.html', books=books, add_form=add_form, aux_form=aux_form, date_form=date_form, debit_form=debit_form,
credit_form=credit_form, montant_form=montant_form, jn_form=jn_form, pid_form=pid_form, ref_form=ref_form,
tp_form=tp_form, ct_form=ct_form, des_form=des_form)
There is a simple form for each query, it works a treat for each single query. Here is the form and html code:
class SearchAuxForm(FlaskForm):
selectaux = QuerySelectField('Aux', query_factory=AUX, get_label='id')
submitaux = SubmitField('submit')
def AUX():
return Auxilliere.query
html:
<div class="AUX">
<form action="{{ url_for('books.search_aux') }}" method="post">
{{ aux_form.selectaux(class="input") }}{{ aux_form.submitaux(class="submit") }}
</form>
</div>
I tried to do this as a single function with one submit button, but it ended in disaster. I have not submitted this as an answer, Because it does not do all I asked but it is a start.
FINAL EDIT:
I would like to thank the person(s) who reopened this question, allowing mr Lucas Scott to provide a fascinating and informative answer to help me and others.
There are many ways to achieve your desired result of being able to query/filter multiple columns in a table. I will give you an example of how I would approach creating an endpoint that will allow you to filter on one column, or multiple columns.
Here is our basic Books model and the /books endpoint as a stub
import flask
from flask_sqlalchemy import SQLAlchemy
app = flask.Flask(__name__)
db = SQLAlchemy(app) # uses in memory sqlite3 db by default
class Books(db.Model):
__tablename__ = "book"
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
title = db.Column(db.String(255), nullable=False)
author = db.Column(db.String(255), nullable=False)
supplier = db.Column(db.String(255))
published = db.Column(db.Date, nullable=False)
db.create_all()
#app.routes("/books", methods=["GET"])
def all_books():
pass
The first step is to decide on a method of querying a collection by using url parameters. I will use fact that multiple instances of the same key in a query parameter are given as lists to allow us to filter on multiple columns.
For example /books?filter=id&filter=author will turn into {"filter": ["id", "author"]}.
For our querying syntax we will use comma separated values for the filter value.
example:
books?filter=author,eq,jim&suplier,eq,self published
Which turns into {"filter": ["author,eq,jim", "supplier,eq,self published"]}. Notice the space in self published. flask will handle the url-encoding for us and give back a string with a space instead of %20.
Let's clean this up a bit by adding a Filter class to represent our filter query parameter.
class QueryValidationError(Exception):
""" We can handle specific exceptions and
return a http response with flask """
pass
class Filter:
supported_operators = ("eq", "ne", "lt", "gt", "le", "ge")
def __init__(self, column, operator, value):
self.column = column
self.operator = operator
self.value = value
self.validate()
def validate(self):
if operator not in self.supported_operators:
# We will deal with catching this later
raise QueryValidationError(
f"operator `{operator}` is not one of supported "
f"operators `{self.supported_operators}`"
)
Now we will create a function for processing our list of filters into a list of Filter objects.
def create_filters(filters):
filters_processed = []
if filters is None:
# No filters given
return filters_processed
elif isinstance(filters, str):
# if only one filter given
filter_split = filters.split(",")
filters_processed.append(
Filter(*filter_split)
)
elif isinstance(filters, list):
# if more than one filter given
try:
filters_processed = [Filter(*_filter.split(",")) for _filter in filters]
except Exception:
raise QueryValidationError("Filter query invalid")
else:
# Programer error
raise TypeError(
f"filters expected to be `str` or list "
f"but was of type `{type(filters)}`"
)
return filters_processed
and now we can add our helper functions to our endpoint.
#app.route("/books", methods=["GET"])
def all_books():
args = flask.request.args
filters = create_filters(args.get("filter"))
SQLAlchemy allows us to do filtering by using operator overloading. That is using filter(Book.author == "some value"). The == here does not trigger the default == behaviour. Instead the creator of SQLAlchemy has overloaded this operator and instead it creates the SQL query that checks for equality and adds it to the
query. We can leverage this behaviour by using the Pythons operator module. For example:
import operator
from models import Book
authors = Book.query.filter(operator.eq(Book.author, "some author")).all()
This does not seem helpful by it's self, but gets us a step closer to creating a generic and dynamic filtering mechanism. The next important step to making this more dynamic is with the built-in getattr which allows us to look up attributes on a given object using strings. Example:
class Anything:
def say_hi(self):
print("hello")
# use getattr to say hello
getattr(Anything, "say_hi") # returns the function `say_hi`
getattr(Anything, "say_hi")() # calls the function `say_hi`
We can now tie this all together by creating a generic filtering function:
def filter_query(filters, query, model):
for _filter in filters:
# get our operator
op = getattr(operator, _filter.operator)
# get the column to filter on
column = getattr(model, _filter.column)
# value to filter for
value = _filter.value
# build up a query by adding multiple filters
query = query.filter(op(column, value))
return query
We can filter any model with our implementation, and not just by one column.
#app.route("/books", methods=["GET"])
def all_books():
args = flask.request.args
filters = create_filters(args.get("filter"))
query = Books.query
query = filter_query(filters, query, Books)
result = []
for book in query.all():
result.append(dict(
id=book.id,
title=book.title,
author=book.author,
supplier=book.supplier,
published=str(book.published)
))
return flask.jsonify(result), 200
Here is everything all together, and including the error handling of validation errors
import flask
import json
import operator
from flask_sqlalchemy import SQLAlchemy
app = flask.Flask(__name__)
db = SQLAlchemy(app) # uses in memory sqlite3 db by default
class Books(db.Model):
__tablename__ = "book"
id = db.Column(db.Integer, primary_key=True, autoincrement=True)
title = db.Column(db.String(255), nullable=False)
author = db.Column(db.String(255), nullable=False)
supplier = db.Column(db.String(255))
published = db.Column(db.Date, nullable=False)
db.create_all()
class QueryValidationError(Exception):
pass
class Filter:
supported_operators = ("eq", "ne", "lt", "gt", "le", "ge")
def __init__(self, column, operator, value):
self.column = column
self.operator = operator
self.value = value
self.validate()
def validate(self):
if self.operator not in self.supported_operators:
raise QueryValidationError(
f"operator `{self.operator}` is not one of supported "
f"operators `{self.supported_operators}`"
)
def create_filters(filters):
filters_processed = []
if filters is None:
# No filters given
return filters_processed
elif isinstance(filters, str):
# if only one filter given
filter_split = filters.split(",")
filters_processed.append(
Filter(*filter_split)
)
elif isinstance(filters, list):
# if more than one filter given
try:
filters_processed = [Filter(*_filter.split(",")) for _filter in filters]
except Exception:
raise QueryValidationError("Filter query invalid")
else:
# Programer error
raise TypeError(
f"filters expected to be `str` or list "
f"but was of type `{type(filters)}`"
)
return filters_processed
def filter_query(filters, query, model):
for _filter in filters:
# get our operator
op = getattr(operator, _filter.operator)
# get the column to filter on
column = getattr(model, _filter.column)
# value to filter for
value = _filter.value
# build up a query by adding multiple filters
query = query.filter(op(column, value))
return query
#app.errorhandler(QueryValidationError)
def handle_query_validation_error(err):
return flask.jsonify(dict(
errors=[dict(
title="Invalid filer",
details=err.msg,
status="400")
]
)), 400
#app.route("/books", methods=["GET"])
def all_books():
args = flask.request.args
filters = create_filters(args.get("filter"))
query = Books.query
query = filter_query(filters, query, Books)
result = []
for book in query.all():
result.append(dict(
id=book.id,
title=book.title,
author=book.author,
supplier=book.supplier,
published=str(book.published)
))
return flask.jsonify(result), 200
I hope this answers your question, or gives you some ideas on how to tackle your problem.
I would also recommend looking at serialising and marshalling tools like marshmallow-sqlalchemy which will help you simplify turning models into json and back again. It is also helpful for nested object serialisation which can be a pain if you are returning relationships.
The following 3 links are not explaining what i really want to achieve in layman's terms
How do I call one Flask view from another one?
Get json from one view by calling it from another view
Call a route from within another route in Flask
I have the following code
#app.route('/rate_isp_service', methods=['GET', 'POST'])
#login_required
def rate_isp_service():
isp_query = db.session.query(Isps)
isp_entries = [dict
(isp_id=isp.isp_id, isp_name=isp.isp_name, isp_description=isp.isp_description) for isp in
isp_query]
services_query = db.session.query(Services)
services_entries = [dict
(service_id=service.service_id, service_name=service.service_name,
service_catergory_id=service.service_catergory_id) for service in
services_query]
ratings_query = db.session.query(Ratings)
ratings_entries = [dict
(ratings_id=rating.ratings_id, rating_value=rating.rating_value,
rating_comment=rating.rating_comment) for rating in
ratings_query]
servicemetric_query = db.session.query(Service_metric)
servicemetric_entries = [dict
(metric_id=metric.metric_id, metric_name=metric.metric_name,
metric_description=metric.metric_description) for metric in
servicemetric_query]
return render_template('rate_isp_service.html', isp_entries=isp_entries, services_entries=services_entries,ratings_entries=ratings_entries)
And this code populates all my drop downs in my html templates wherever there is a form.
I have had to include this code multiple times in all the views since i cant find a way to include it in some of the views
The approach i wanted to take was creating a view like this
#app.route('/dropdowns', methods=['GET', 'POST'])
#login_required
def dropdowns():
that code here
and be able to call that dropdwon function in any route or view i want
Why don't you put it in a function and call it whenever you want. Like this:
def new_func()
isp_query = db.session.query(Isps)
isp_entries = [dict
(isp_id=isp.isp_id, isp_name=isp.isp_name,isp_description=isp.isp_description) for isp in
isp_query]
services_query = db.session.query(Services)
services_entries = [dict
(service_id=service.service_id, service_name=service.service_name,
service_catergory_id=service.service_catergory_id) for service in
services_query]
ratings_query = db.session.query(Ratings)
ratings_entries = [dict
(ratings_id=rating.ratings_id,rating_value=rating.rating_value,
rating_comment=rating.rating_comment) for rating in
ratings_query]
servicemetric_query = db.session.query(Service_metric)
servicemetric_entries = [dict
(metric_id=metric.metric_id, metric_name=metric.metric_name,
metric_description=metric.metric_description) for metric in
servicemetric_query]
return result1, result2, result3
#app.route('/rate_isp_service', methods=['GET', 'POST'])
#login_required
def rate_isp_service():
result1, result2, result3 = new_func()
A better approach would be to make a utils.py in the same folder and put this new function in it, import it and use it whenever needed.
I have
def newsprofile(request, newstitle, newsid):
newsobj = get_object_or_404(NewsModel, pk=int(newsid))
return render(request, 'newsprofile.html', {'newsobj': newsobj})
but now, if I change the id 1 to 2 in url inside adressbar and hit the enter button e.g. /sometitle_and_and_blabla/1/,
i will get another news but the title doesnot change, it only becomes like:
/sometitle_and_and_blabla/2/
How can I change the title also if id changes?
the urls.py looks like this:
url(r'^news/(?P<newstitle>[^\/]*)/(?P<newsid>\d+)/$', 'newsprofile', name='newsprofile'),
Try like this,
def newsprofile(request, newstitle, newsid):
newsobj = get_object_or_404(NewsModel, pk=int(newsid))
if newstitle != newsobj.newstitle:
return HttpResponsePermanentRedirect('/%s/%s/' % (newsobj.newstitle, newsid))
.....
As you are using named urls (e.g. newsprofile) I recommend the following solution. This is flexible and easy to maintain, even if your urls change as long as you use the same url parameters:
from django.http import HttpResponseRedirect
...
def newsprofile(request, newstitle, newsid):
newsobj = get_object_or_404(NewsModel, pk=int(newsid))
if newsobj.newstitle != newstitle:
return HttpResponseRedirect(reverse("newsprofile", args=[newstitle, newsid]))
return render(request, 'newsprofile.html', {'newsobj': newsobj})
See Django docs here for reverse resolution of URLs.
I am trying to get a 'GET' parameter from one of my template pages, called 'id' (ex. issues.html?id=1), and using it to perform a variety of retrievals from my sqlite database. However, when I run the following code, I get the error "'QueryDict' object has no attribute 'id'"
Here is some of my code in views.py:
def issues(request):
# Retrive basic legislation details from GET parameter
legislation_id = request.GET.id
legislation = Legislation.objects.filter(id = legislation_id)[0]
# Getter functions from database - names are pretty self-explanatory
def get_buttons():
button_html = ""
for tag in legislation.demographic_tags:
button_html += "<input type='button' class='button' onclick='showtag"+tag.hash_code+"();' value='"+tag.name+"'>"
return button_html
def get_description():
return legislation.description
def get_script():
return ""
def get_sponsor():
return legislation.sponsor
def get_summary():
return legislation.summary
def get_title():
return legislation.name
# Return results back to page
return render(request, 'issues.html',
{'buttons': get_buttons(), 'description': get_description(), 'script': get_script(), 'sponsor': get_sponsor(),
'summary': get_summary(), 'title': get_title()})
Your problem seems to be here: legislation_id = request.GET.id
request.GET is a dictionary so you need to get its key like this:
legislation_id = request.GET["id"]
You can also get the key with dict's get method as #Alvaro suggested: request.GET.get("id", 0). This will return 0 as default if id key ain't present and save you from KeyError exception.
Hope this helps!
I have a script, migrating Image to a custom type, for my Plone instance. Its partial code sample looks like this:
class ImagesToPhotosMigrator(InplaceATItemMigrator):
src_portal_type = 'Image'
src_meta_type = 'ATBlob'
dst_portal_type = 'Photo'
dst_meta_type = 'Photo'
def last_migrate_reindex(self):
self.new.reindexObject(idxs=['object_provides', 'portal_type',
'Type', 'UID'])
fields_map = {
}
def getImagesToPhotosMigrationWalker(self):
return getMigrationWalker(self, migrator=ImagesToPhotosMigrator)
def migrateImages(self):
walker = getImagesToPhotosMigrationWalker(self)
walker.go()
return walker.getOutput()
The script works, but I want the migration only happens in a specific folder, say /my-folder, what to add in the script?
You should have specified that you refer to Products.contentmigration, cause it's not implicit in the words "content migration" (lately there are more kind of migrations than lines of code). Anyway, here your solution (CustomQueryWalker is the key):
from Products.contentmigration.walker import CustomQueryWalker
def getImagesToPhotosMigrationWalker(self, query):
return CustomQueryWalker(self, ImagesToPhotosMigrator, query)
def migrateImages(self):
walker = getImagesToPhotosMigrationWalker(self, {'path' : '/youfolder'})
walker.go()
return walker.getOutput()
Note that the query parameter is a catalog query, therefore you can specify the path, the portal_type or any index in your catalog.