I built a PyQt application to showcase object detection. The detector was trained using haar classifier, whose ouptut is a cascade.xml file.
I tried to package this application using pyinstaller. However, before this, i made a resources.qrc file which i compiled.
<!DOCTYPE RCC><RCC version="1.0">
<qresource>
<file>cascade.xml</file>
</qresource>
</RCC>
My issue is that when i use this resource, via
:/cascade.xml
the file is not read.
What can i do to fix this.
You first need to create a python module from your .qrc file with pyrcc
pyrcc5 resources.qrc -o resources.py
The output of pyrcc then needs to be imported into your python code
import resources
Then you should be able to access the resource through ':/cascade.xml'. In some cases it may be necessary to use 'qrc:/cascade.xml'
The resource path must still, however, be treated like a file on disk. In order to access its contents you will need to read from the resource. Here's an example of how to read and parse it using lxml
import lxml.etree as etree
from PyQt5 import QtCore
# Import the resource module create by pyrcc
import resources
# QFile knows how to read Qt resources
xml_file = QtCore.QFile(':/cascade.xml')
if xml_file.open(QtCore.QFile.ReadOnly):
# Read the QFile and convert QByteArray output to python string
xml_str = str(xml_file.readAll())
# parse the xml document from string
xml_tree = etree.ElementTree(etree.fromstring(xml_str))
xml_file.close()
Related
I want to parse c source code for extracting variables and functions from it. Is there any library available for this purpose?
I tried to achieve it through query language available in tree-sitter parser generator but when I run the program it says undefined reference to the query functions used in the file even I have included the header file (api.h) containing query functions. I tried to resolve these errors but couldn't so looking for some other library which can serve the purpose.
It's better to do it with Clang (e.g. cindex Python API).
For example, to find all function definitions in a translation unit:
#!/usr/bin/env python3
import sys
import clang.cindex
def find_functions(node):
if node.kind == clang.cindex.CursorKind.FUNCTION_DECL:
nm = node.spelling
print(f"Function {nm}")
else:
for c in node.get_children():
find_functions(c)
index = clang.cindex.Index.create()
tu = index.parse(sys.argv[1])
print('Translation unit:', tu.spelling)
find_functions(tu.cursor)
I'm trying to create a code generator that takes input a JSON file and generates multiple classes in multiple files.
And my question is, is it possible to create multiple files for one input using build from dart lang?
Yes it is possible. There are currently many tools in available on pub.dev that have code generation. For creating a simple custom code generator, check out the package code_builder provided by the core Dart team.
You can use dart_style as well to format the output of the code_builder results.
Here is a simple example of the package in use (from the package's example):
import 'package:code_builder/code_builder.dart';
import 'package:dart_style/dart_style.dart';
final _dartfmt = DartFormatter();
// The string of the generated code for AnimalClass
String animalClass() {
final animal = Class((b) => b
..name = 'Animal'
..extend = refer('Organism')
..methods.add(Method.returnsVoid((b) => b
..name = 'eat'
..body = refer('print').call([literalString('Yum!')]).code)));
return _dartfmt.format('${animal.accept(DartEmitter())}');
}
In this example you can use the dart:io API to create a File and write the output from animalClass() (from the example) to the file:
final animalDart = File('animal.dart');
// write the new file to the disk
animalDart.createSync();
// write the contents of the class to the file
animalDart.writeAsStringSync(animalClass());
You can use the File API to read a .json from the path, then use jsonDecode on the contents of the file to access the contents of the JSON config.
I am using kivy as the GUI and Briefcase as a packaging utility. My .kv file is in the appname/project/src/projectName/resources folder. I also need a .csv file, in the same folder, and want to use pandas with it. I have no problem with importing the packages (I added them to the .toml file). I can't use the full path because when I package the app, the path will be different on each computer. Using relative paths to the app.py file does not work, giving me a file not found error. Is there a way to read a file using a relative path (maybe the source parameter in the .toml file)?
kv = Builder.load_file('resources/builder.kv')
df = pd.read_csv('resources/chemdata.csv')
class ChemApp(App):
def build(self):
self.icon = 'resources/elemental.ico'
return kv
I just encountered and solved a similar problem with Briefcase, even though I was using BeeWare's Toga GUI.
In my case, the main Python file app.py had to access a database file resources/data.csv. In the constructor of the class where I create a main window in app.py, I added the following lines (The import line wasn't there, but included here for clarification):
from pathlib import Path
self.resources_folder = Path(__file__).joinpath("../resources").resolve()
self.db_filepath = self.resources_folder.joinpath("data.csv")
Then I used self.db_filepath to successfully open the CSV file on my phone.
__file__ returns the path to the current file on whatever platform or device.
My filename contains information that I need in my pipeline, for example the identifier for my data points is part of the filename and not a field in the data. e.g Every wind turbine generates a file turbine-loc-001-007.csv. e.g And I need the loc data within the pipeline.
Java (sdk 2.9.0):
Beams TextIO readers do not give access to the filename itself, for these use cases we need to make use of FileIO to match the files and gain access to the information stored in the file name. Unlike TextIO, the reading of the file needs to be taken care of by the user in transforms downstream of the FileIO read. The results of a FileIO read is a PCollection the ReadableFile class contains the file name as metadata which can be used along with the contents of the file.
FileIO does have a convenience method readFullyAsUTF8String() which will read the entire file into a String object, this will read the whole file into memory first. If memory is a concern you can work directly with the file with utility classes like FileSystems.
From: Document Link
PCollection<KV<String, String>> filesAndContents = p
.apply(FileIO.match().filepattern("hdfs://path/to/*.gz"))
// withCompression can be omitted - by default compression is detected from the filename.
.apply(FileIO.readMatches().withCompression(GZIP))
.apply(MapElements
// uses imports from TypeDescriptors
.into(KVs(strings(), strings()))
.via((ReadableFile f) -> KV.of(
f.getMetadata().resourceId().toString(), f.readFullyAsUTF8String())));
Python (sdk 2.9.0):
For 2.9.0 for python you will need to collect the list of URI from outside of the Dataflow pipeline and feed it in as a parameter to the pipeline. For example making use of FileSystems to read in the list of files via a Glob pattern and then passing that to a PCollection for processing.
Once fileio see PR https://github.com/apache/beam/pull/7791/ is available, the following code would also be an option for python.
import apache_beam as beam
from apache_beam.io import fileio
with beam.Pipeline() as p:
readable_files = (p
| fileio.MatchFiles(‘hdfs://path/to/*.txt’)
| fileio.ReadMatches()
| beam.Reshuffle())
files_and_contents = (readable_files
| beam.Map(lambda x: (x.metadata.path,
x.read_utf8()))
I know you can use the library, import and even #import, but which is correct?
I have got two files, MainClass.dart and Library.Dart, and I want to add a reference to Library.dart in MainClass.dart. How can I do that?
Firstly let me just preface this by saying please do not use the hash symbol before import or library or anything else. This is an old syntax that is being deprecated. So we no longer want to use #import('...') The correct syntax is:
import 'some_file.dart';
That said, there are two different things we can do to access different dart source files within our current file. The first is to import the file. We use this such as in your case when you want to bring a different library into the current file (or more accurately current library).
Usually if your files are in the same directory, or a sub directory of the current one we would import them like this:
import 'lib/library.dart';
However If you are using the pub package layout you can also use some special short-cut references as well to import files (particularly from other packages you've imported). I highly suggest reading the documents on the pub site, as most applications and libraries are designed with this in mind. It also has suggestions on best naming conventions such as filenames in all lower case, and using underscore for spaces, and directory layouts.
The other important thing to know about bringing a dart file into another file, is that we can use the part and part of directives. This used to be called #source but was changed (with the removal of the hash sign) to reduce confusion. The part directive is used when we want to write a single library which spans multiple files. Say for instance you have an Awesome Library, which is starting to get a little large for a single file. We will create the main file of the library (not to be confused with the main method). This file will usually have the same name as the library itself.
// awesome_library.dart
library awesome_library;
import 'dart:math';
import '...';
// this injects all the content of secret_file.dart
// into this file right here almost as if it was
// here in the first place.
part 'src/secret_file.dart';
// The rest of our file here
// ...
The part directive basically takes everything from our src/secret_file.dart and inserts it into that part of the file. This allows us to split our huge Awesome Library into multiple smaller files that are easier to maintain. While not specifically required, it is helpful to use the part of directive in our secret_file.dart to help the editor know that it is "part of" the library.
// secret_file.dart
part of awesome_library;
// ... Rest of our secret_file code below.
Note that when using a part file like this, the part(s) (that is everything that is not the main file of the library) cannot import or use library declarations themselves. They import whatever is imported into the the main file, but they cannot add any additional imports.
For more information about library see this link.
Importing your own created libraries:
You will be importing the filename.dart and not the name of your library.
So if the name of your library is: myLib and it is saved in the file: someDartFile.dart you will have to
import 'someDartFile.dart';
If you have on Windows a library at: K:\SomeDir\someFile.dart you will need to write:
import '/K:/SomeDir/someFile.dart';
example:
import 'LibraryFile.dart'; //importing myLib
void main(){
//a class from myLib in the LibraryFile.dart file
var some = new SomeClassFromMyLibrary();
}
myLib in LibraryFile.dart:
library myLibrary;
import 'dart:math';
class SomeClassFromMyLibrary{
String _str = "this is some private String only to myLibrary";
String pubStr = "created instances of this class can access";
}
Here a full example.
//TestLib.dart
import 'LibFile.dart'; //SomeLibrary
void main() {
print("Hello, World!");
LibFile l = new LibFile();
print(l.publicString);//public
print(l.getPrivateString);//private
print(l.getMagicNumber); //42
}
//LibFile.dart
library SomeLibrary;
part 'LibFile2.dart';
class LibFile {
String _privateString = "private";
String publicString = "public";
String get getPrivateString => _privateString;
int get getMagicNumber => new LibFile2().number;
}
//LibFile2.dart
part of SomeLibrary;
class LibFile2 {
int number = 42;
}
Although i am answering very late, but the answer may help new developer.
Always use pubspec.yaml file in your dart package(application/library).
once you run pub get command it will add your local library in the dependencies list in .packages file.
Consider i have following project structure.
To refer to the content of greeting.dart in my main.dart file i should add the library as below
import 'package:my_project_name/greeting.dart'
Once imported we can use the content of greeting.dart file in our main.dart file.
Note: we have not used the actual path as you can see 'lib' directory is missing.
First make sure that's the name which you have mentioned in pubspec.yaml and the file you want to import are sharing the exact same name
example:
pubspec.yaml
name: flutter_wordpress_app
description: flutter wordpress app
...
....
// dirOne/dirTwo/greeting.dart
class FavArticleBloc {
// Your code goes here
}
import 'package:flutter_wordpress_app/dirOne/dirTwo/greeting.dart'
void main(){
var some = new FavArticleBloc();
}
But
in the main.dartyou don't need to specify
import 'package:flutter_wordpress_app
just do like below
import 'dirOne/dirTwo/greeting.dart