Entry with suggestions - python

I'm building a small PyGTK application and I have an text input field (currently a ComboBoxEntry) which is populated with a few values that the user should be able to choose from.
I think what I want to do is to filter out the matching fields and only show those ones so the user using the keyboard arrows can choose one of the matching ones.
To give some background the predefined values are a bunch of urls and the user should be able to choose from theese or fill in a new one.
Example:
the predefined urls:
http://www.google.com
http://www.google.com/android
http://www.greatstuff.com
http://www.facebook.com
When a user types 'http://www.g'
The three URLs starting with that string is to be shown (in some way) and when typeing 'http://www.goog' the two starting with that is to be shown
Any Ideas?

An Entry with an EntryCompletion seems more appropriate than a ComboBoxEntry. As always, the tutorial is a good start.
It's very easy to set up when the predefined URLs list is small and fixed.
You just need to populate a ListStore:
# simplified example from the tutorial
import gtk
urls = [
'http://www.google.com',
'http://www.google.com/android',
'http://www.greatstuff.com',
'http://www.facebook.com',
]
liststore = gtk.ListStore(str)
for s in urls:
liststore.append([s])
completion = gtk.EntryCompletion()
completion.set_model(liststore)
completion.set_text_column(0)
entry = gtk.Entry()
entry.set_completion(completion)
# boilerplate
window = gtk.Window()
window.add(entry)
window.connect('destroy', lambda w: gtk.main_quit())
window.show_all()
gtk.main()
Users are not likely to bother typing "http://" or even "www.", so you probably want to match any part of the URL (e.g. just "og" works!):
def match_anywhere(completion, entrystr, iter, data):
modelstr = completion.get_model()[iter][0]
return entrystr in modelstr
completion.set_match_func(match_anywhere, None)
This will test every value in the ListStore for a match, so it's not scalable to huge lists (I mean huge; a 1000 works fine).
Be sure to play with the various options of EntryCompletion, to configure the most pleasant behavior.

You may want to look at how Deskbar Applet's Cuemiac does it.

Well, you obviously want to deal with prefixes so you'll probably want to use some sort of trie. Of course, there are issues to deal with. For instance, after a person has typed in a few letters ( or maybe even just one) you will want to either traverse the rest of the branches of the trie to find suggestions, or have suggestions stored in each node. A lot of these sorts of decisions depend on how many possible suggestions you plan on having.

Related

QtreeWidget python read the state of the checked boxes

First sorry if I am missing anything.and sorry about the format, new to stackoverflow
I am trying to read the flag state from a QtreeWidget.
I have tried a lot of things and nothing seam to work.
I am dynamical creating the tree as follows
Part=str(result2[row2][0])
qty=str(offset_B)+str(result2[row2][1])
instock=str(offset_B)+str(result2[row2][2])
B = QTreeWidgetItem(A, [Part,qty,instock])
B.setForeground(0,QtGui.QBrush(QtGui.QColor(color_item)))
B.setForeground(1,QtGui.QBrush(QtGui.QColor(color_item)))
B.setForeground(2,QtGui.QBrush(QtGui.QColor(color_item)))
B.setFlags(Qt.ItemIsTristate)
B.setCheckState(0, Qt.Unchecked)
I have a button Generate Po's and when I click it I want to iterate through the items and grab the text value of the checked Items.
sample
so it should return a list of some sort with all the text field.
I can do the list I just need to understand how to grab the "State" of the button.
I hope this is clear enough.

Basics of connecting python to the web and validating user input

I'm relatively new, and I'm just at a loss as to where to start. I don't expect detailed step-by-step responses (though, of course, those are more than welcome), but any nudges in the right direction would be greatly appreciated.
I want to use the Gutenberg python library to select a text based on a user's input.
Right now I have the code:
from gutenberg.acquire import load_etext
from gutenberg.cleanup import strip_headers
text = strip_headers(load_etext(11)).strip()
where the number represents the text (in this case 11 = Alice in Wonderland).
Then I have a bunch of code about what to do with the text, but I don't think that's relevant here. (If it is let me know and I can add it).
Basically, instead of just selecting a text, I want to let the user do that. I want to ask the user for their choice of author, and if Project Gutenberg (PG) has pieces by that author, have them then select from the list of book titles (if PG doesn't have anything by that author, return some response along the lines of "sorry, don't have anything by $author_name, pick someone else." And then once the user has decided on a book, have the number corresponding to that book be entered into the code.
I just have no idea where to start in this process. I know how to handle user input, but I don't know how to take that input and search for something online using it.
Ideally, I'd be able to handle things like spelling mistakes too, but that may be down the line.
I really appreciate any help anyone has the time to give. Thanks!
The gutenberg module includes facilities for searching for a text by metadata, such as author. The example from the docs is:
from gutenberg.query import get_etexts
from gutenberg.query import get_metadata
print(get_metadata('title', 2701)) # prints frozenset([u'Moby Dick; Or, The Whale'])
print(get_metadata('author', 2701)) # prints frozenset([u'Melville, Hermann'])
print(get_etexts('title', 'Moby Dick; Or, The Whale')) # prints frozenset([2701, ...])
print(get_etexts('author', 'Melville, Hermann')) # prints frozenset([2701, ...])
It sounds as if you already know how to read a value from the user into a variable, and replacing the literal author in the above would be as simple as doing something like:
author_name = my_get_input_from_user_function()
texts = get_etexts('author', author_name)
Note the following note from the same section:
Before you use one of the gutenberg.query functions you must populate the local metadata cache. This one-off process will take quite a while to complete (18 hours on my machine) but once it is done, any subsequent calls to get_etexts or get_metadata will be very fast. If you fail to populate the cache, the calls will raise an exception.
With that in mind, I haven't tried the code I've presented in this answer because I'm still waiting for my local cache to populate.

How can I query for multiple properties not known in advance using Expando?

I'm making an application in which a user can create categories to put items in them. The items share some basic properties, but the rest of them are defined by the category they belong to. The problem is that both the category and it's special properties are created by the user.
For instance, the user may create two categories: books and buttons. In the 'book' category he may create two properties: number of pages and author. In the buttons category he may create different properties: number of holes and color.
Initially, I placed these properties in a JsonProperty inside the Item. While this works, it means that I query the Datastore just by specifying the category that I am looking for and then I have to filter the results of the query in the code. For example, if I'm looking for all the books whose author is Carl Sagan, I would query the Item class with category == books and the loop through the results to keep only those that match the author.
While I don't really expect to have that many items per category (probably in the hundreds, unlikely to get to one thousand), this looks inefficient. So I tried to use ndb.Expando to make those special properties real properties that are indexed. I did this, adding the corresponding special properties to the item when putting it to the Datastore. So if the user creates an Item in the 'books' category and previously created in that category the special property 'author', an Item is saved with the special property expando_author = author in it. It worked as I expected until this point (dev server).
The real problem though became visible when I did some queries. While they worked in the dev server, they created composite indexes for each special/expando property, even if the query filters were equality only. And while each category can have at most five properties, it is evident that it can easily get out of control.
Example query:
items = Item.query()
for p in properties:
items = items.filter(ndb.GenericProperty(p)==properties[p])
items.fetch()
Now, since I don't know in advance what the properties will be (though I will limit it to 5), I can't build the indexes before uploading the application, and even if I knew it would probably mean having more indexes that I'm comfortable with. Is Expando the wrong tool for what I'm trying to do? Should I just keep filtering the results in the code using the JsonProperty? I would greatly appreciate any advice I can get.
PD. To make this post shorter I omitted a few details about what I did, if you need to know something I may have left out just ask in the comments.
Consider storing category's properties in a single list property prefixed with category property name.
Like (forget me I forgot exact Python syntax, switched to Go)
class Item():
props = StringListProperty()
book = Item(category='book', props=['title:Carl Sagan'])
button = Item(category='button', props=['wholes:5'])
Then you can do have a single composite index on category+props and do queries like this:
def filter_items(category, propName, propValue):
Item.filter(Item.category == category).filter(Item.props==propName+':'+propValue)
And you would need a function on Item to get property values cleaned up from prop names.

Searching a TreeView

I am working on a project and am using a treeview. I have done lots of searching and all ive found to my answer is to itterate through the whole treeview but not even how to do it, so my question is how do i search a treeview for an item that contains an input string. The idea will be to have an entry box and have users type something in there, when they press search items that contain what the user has input is shown. I'm not sure if i could do this in the treeview or if it will have to go into a listview. I'm on windows 7 pyqt5 python 3.5
self.treeView = QtWidgets.QTreeView(self.centralWidget)
self.treeView.setSortingEnabled(True)
self.treeView.setObjectName("treeView")
self.horizontalLayout_4.addWidget(self.treeView)
self.file_model=QtWidgets.QFileSystemModel()
self.file_model.setRootPath('C:\My Stuff\Movies')
self.treeView.setModel(self.file_model)
self.treeView.setRootIndex(self.file_model.index('C:\My Stuff\Movies'))
self.treeView.setHeaderHidden(True)
self.treeView.hideColumn(1)
self.treeView.hideColumn(2)
self.treeView.hideColumn(3)
This answer is an outline of the solution.
You may find the code I wrote for SCM Workbench useful for reference:
https://github.com/barry-scott/scm-workbench/blob/master/Source/Scm/wb_scm_table_model.py
In my app the function indexFromBookmark() I think is close to what you
want.
To start you need the root of the tree. You get that item with self.invisibleRootItem().
You can ask two interesting things of the item. Its name from item.text() and its children by calling item.child( row ) where the row starts from 0.
When the item of interest is found you can turn the item into an index using indexFromItem(). You need an index to set the selection in the tree for example.
With file names I guess you split on '\' and each items text() is the path part.

What is the most efficient way to do a ONE:ONE relation on google app engine datastore

Even with all I do know about the AppEngine datastore, I don't know the answer to this. I'm trying to avoid having to write and run all the code it would take to figure it out, hoping someone already knows the answer.
I have code like:
class AddlInfo(db.Model)
user = db.ReferenceProperty(User)
otherstuff = db.ListProperty(db.Key, indexed=False)
And create the record with:
info = AddlInfo(user=user)
info.put()
To get this object I can do something like:
# This seems excessively wordy (even though that doesn't directly translate into slower)
info = AddlInfo.all().filter('user =', user).fetch(1)
or I could do something like:
class AddlInfo(db.Model)
# str(user.key()) is the key to this record
otherstuff = db.ListProperty(db.Key, indexed=False)
Creation looks like:
info = AddlInfo(key_name=str(user.key()))
info.put()
And then get the info with:
info = AddlInfo.get(str(user.key()))
I don't need the reference_property in the AddlInfo, (I got there using the user object in the first place). Which is faster/less resource intensive?
==================
Part of why I was doing it this way is that otherstuff could be a list of 100+ keys and I only need them sometimes (probably less than 50% of the time) I was trying to make it more efficient by not having to load those 100+ keys on every request.....
Between those 2 options, the second is marginally cheaper, because you're determining the key by inference rather than looking it up in a remote index.
As Wooble said, it's cheaper still to just keep everything on one entity. Consider an Expando if you just need a way to store a bunch of optional, ad-hoc properties.
The second approach is the better one, with one modification: There's no need to use the whole key of the user as the key name of this entity - just use the same key name as the User record.

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