I am hoping to return and print a dictionary of the files and their file size, what I have written is this;
file_size = {}
for fn in glob.glob('*'):
with os.stat(fn) as f:
file_size[fn] = f.st_size
print (file_size)
But I am getting the AtributeError: enter
To use with statement you need to have the methods __enter__() and __exit__() in the object methods.
That is not the case for os.stat(). Remove the with statement and your problem will be fixed:
import glob, os
file_size = {}
for fn in glob.glob('*'):
f = os.stat(fn)
file_size[fn] = f.st_size
print (file_size)
Related
I want learn methods refineXXX of zio library.
For this purpose I write simple code
import zio.ZIOAppDefault
import zio.Unsafe.unsafe
import zio._
import java.sql.SQLException
object Bot extends ZIOAppDefault {
val codeWithExc: ZIO[Any,Throwable,Int] =
ZIO.fail(new SQLException("message of SQL error."))
val MainApp: ZIO[Any, Throwable, Int] = for {
_ <- Console.printLine("Begin")
res <- codeWithExc
_ <- Console.printLine(s" res = $res")
} yield res
def run: URIO[ZIOAppArgs, ExitCode] =
for {
res <- MainApp.exitCode
} yield res
}
unsafe{ implicit u =>
Runtime.default.unsafe.run(Bot.run.provide(ZIOAppArgs.empty))
}
When I run it in IDEA worksheet I see output:
Begin
res0: zio.Exit[Nothing,zio.ExitCode] = Success(ExitCode(1))
and expect fail in res <- codeWithExc and death of the main fiber.
The problem here is that You are mapping ZIO to .exitCode which returns URIO that cannot really fail. Failure will be mapped to success and the only reason to tell that it did actually fail is to verify that ExitCode was not 0. If You change Your code and replace that with something like below, it will look work correctly:
def run = MainApp
I've created a dictionary from an Uploaded file in Django.
This dictionary has a nested list of dictionaries:
file = {"name": "filename", "sections": [{"section_name": "string", "lines": [{line_number: 0, "line"; "data"}]}], "etc": "etc"}
The model represents the dictionaries depth too.
class Line(EmbeddedDocument):
line_number = IntField()
line = StringField()
definition = ReferenceField(Definition)
class Section(EmbeddedDocument):
section_name = StringField()
lines = EmbeddedDocumentListField(Line))
class File(Document):
name = StringField()
sections = EmbeddedDocumentListField(Section))
created_on = DateTimeField()
created_by = StringField()
modified_on = DateTimeField()
modified_by = StringField()
In the POST I have the following to chop the file up into the above Dict (the file is a simple text file):
file= {}
with open(os.path.join(path, filename + ".txt"), 'r') as temp_file:
filelines = temp_file.readlines()
sections = []
section = {}
lines = []
for i, l in enumerate(filelines):
if i == 0:
section["section_name"] = "Top"
elif '*' in l:
if l.index('*') == 0 and '*' not in lines[len(lines) - 2"line"]:
section["lines"] = lines
lines = []
sections.append(section)
section = dict()
section["section_name"] = filelines[i + 1][1:-2]
line = {"line_number": i + 1, "line": l}
lines.append(line)
section['lines'] = lines
sections.append(section)
file["name"] = filename
file["sections"] = sections
I will tidy this up eventually.
Once the dict has been made how do I serialise it using the serializer?
Is it possible to insert this into a serializer?
If not how can I get it all into the database with validation?
I've tried json.dumps() and JsonRequst() then putting them in data= for the serializer but get Unable to get repr for <class '....'>
I'm pretty new to Django and MongoDB so if you need more info I can provide :)
Thanks!
Update
Change the model's List Fields to EmbeddedDocumentListField as suggest in the answer.
Answered
Thanks to Boris' suggestion below it pointed me to an error I wasn't getting initially. I had a typo and passing the dict directly into FileSerializer(data=file) works like a charm! :)
James!
The easiest way to validate that your incoming JSONs adhere to the Mongoengine Documents schema that you've specified is to use DRF-Mongoengine's DocumentSerializer.
Basically, what you need to do is create a serializer
serializers.py
import rest_framework_mongoengine
class FileSerializer(rest_framework_mongoengine.DocumentSerializer):
class Meta:
fields = '__all__'
model = File
Then you need a view or viewset that makes use of this Serializer to respond to GET/POST/PUT/DELETE requests.
views.py
from rest_framework_mongoengine import viewsets
class FileViewSet(viewsets.ModelViewSet):
lookup_field = 'id'
serializer_class = FileSerializer
def get_queryset(self):
return File.objects.all()
and register this viewset with a router
urls.py
from rest_framework import routers
# this is DRF router for REST API viewsets
router = routers.DefaultRouter()
# register REST API endpoints with DRF router
router.register(r'file', FileViewSet, r"file")
I'd also recommend using EmbeddedDocumentListField instead of ListField(EmbeddedDocumentField(Section)) - it has additional methods.
I recently saw code for reading entire contents of an InputStream into a String in Kotlin, such as:
// input is of type InputStream
val baos = ByteArrayOutputStream()
input.use { it.copyTo(baos) }
val inputAsString = baos.toString()
And also:
val reader = BufferedReader(InputStreamReader(input))
try {
val results = StringBuilder()
while (true) {
val line = reader.readLine()
if (line == null) break
results.append(line)
}
val inputAsString = results.toString()
} finally {
reader.close()
}
And even this that looks smoother since it auto-closes the InputStream:
val inputString = BufferedReader(InputStreamReader(input)).useLines { lines ->
val results = StringBuilder()
lines.forEach { results.append(it) }
results.toString()
}
Or slight variation on that one:
val results = StringBuilder()
BufferedReader(InputStreamReader(input)).forEachLine { results.append(it) }
val resultsAsString = results.toString()
Then this functional fold thingy:
val inputString = input.bufferedReader().useLines { lines ->
lines.fold(StringBuilder()) { buff, line -> buff.append(line) }.toString()
}
Or a bad variation which doesn't close the InputStream:
val inputString = BufferedReader(InputStreamReader(input))
.lineSequence()
.fold(StringBuilder()) { buff, line -> buff.append(line) }
.toString()
But they are all clunky and I keep finding newer and different versions of the same... and some of them never even close the InputStream. What is a non-clunky (idiomatic) way to read the InputStream?
Note: this question is intentionally written and answered by the author (Self-Answered Questions), so that the idiomatic answers to commonly asked Kotlin topics are present in SO.
Kotlin has a specific extension just for this purpose.
The simplest:
val inputAsString = input.bufferedReader().use { it.readText() } // defaults to UTF-8
And in this example, you could decide between bufferedReader() or just reader(). The call to the function Closeable.use() will automatically close the input at the end of the lambda's execution.
Further reading:
If you do this type of thing a lot, you could write this as an extension function:
fun InputStream.readTextAndClose(charset: Charset = Charsets.UTF_8): String {
return this.bufferedReader(charset).use { it.readText() }
}
Which you could then call easily as:
val inputAsString = input.readTextAndClose() // defaults to UTF-8
On a side note, all Kotlin extension functions that require knowing the charset already default to UTF-8, so if you require a different encoding you need to adjust the code above in calls to include encoding for reader(charset) or bufferedReader(charset).
Warning: You might see examples that are shorter:
val inputAsString = input.reader().readText()
But these do not close the stream. Make sure you check the API documentation for all of the IO functions you use to be sure which ones close and which do not. Usually, if they include the word use (such as useLines() or use()) they close the stream after. An exception is that File.readText() differs from Reader.readText() in that the former does not leave anything open and the latter does indeed require an explicit close.
See also: Kotlin IO related extension functions
【Method 1 | Manually Close Stream】
private fun getFileText(uri: Uri):String {
val inputStream = contentResolver.openInputStream(uri)!!
val bytes = inputStream.readBytes() //see below
val text = String(bytes, StandardCharsets.UTF_8) //specify charset
inputStream.close()
return text
}
inputStream.readBytes() requires manually close the stream: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/java.io.-input-stream/read-bytes.html
【Method 2 | Automatically Close Stream】
private fun getFileText(uri: Uri): String {
return contentResolver.openInputStream(uri)!!.bufferedReader().use {it.readText() }
}
You can specify the charset inside bufferedReader(), default is UTF-8:
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/java.io.-input-stream/buffered-reader.html
bufferedReader() is an upgrade version of reader(), it is more versatile:
How exactly does bufferedReader() work in Kotlin?
use() can automatically close the stream when the block is done:
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/use.html
An example that reads contents of an InputStream to a String
import java.io.File
import java.io.InputStream
import java.nio.charset.Charset
fun main(args: Array<String>) {
val file = File("input"+File.separator+"contents.txt")
var ins:InputStream = file.inputStream()
var content = ins.readBytes().toString(Charset.defaultCharset())
println(content)
}
For Reference - Kotlin Read File
Quick solution works well when converting InputStream to string.
val convertedInputStream = String(inputStream.readAllBytes(), StandardCharsets.UTF_8)
I am trying to pass contextInfo of typeUnsafeMutablePointer<Void> to UISaveVideoAtPathToSavedPhotosAlbum and use it in the callback function. For some reason I am unable to access contextInfo as a string using UnsafePointer<String>(x).memory when I am in the callback function.
I am pretty sure it is something simple I am missing but have spent way to many hours trying to figure this out.
Below is some code that I have tried.
The following code works.
var testStr:String = "hello"
takesAMutableVoidPointer(&testStr)
func takesAMutableVoidPointer(x: UnsafeMutablePointer<Void>){
var pStr:String = UnsafePointer<String>(x).memory
println("x = \(x)")
println("pStr = \(pStr)")
}
However the following code does not work.
var testStr:String = "hello"
if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(filePath){ //the filePath is compatible
println("Compatible")
//UISaveVideoAtPathToSavedPhotosAlbum(filePath, self, nil, nil)
UISaveVideoAtPathToSavedPhotosAlbum(filePath, self, "video:didFinishSavingWithError:contextInfo:", &testStr)
}
else{
println("Not Compatible")
}
func video(video: NSString, didFinishSavingWithError error:NSError, contextInfo:UnsafeMutablePointer<Void>){
var pStr:String = UnsafePointer<String>(contextInfo).memory
println("contextInfo = \(contextInfo)")
println("pStr = \(pStr)")
}
Once I get to the following line:
var pStr:String = UnsafePointer<String>(contextInfo).memory
I keep getting the following error:
Thread 1: EXC_BAD_ACCESS(code=1, address=0x0)
Any help with this would be greatly appreciated.
Thanks.
Update
Rintaro commented that testStr needs to be top level but the following code works.
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var testStr:String = "hello"
takesAMutableVoidPointer(&testStr)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func takesAMutableVoidPointer(x: UnsafeMutablePointer<Void>){
var answer = UnsafePointer<String>(x).memory
println("x = \(x)")
println("answer = \(answer)")
}
}
I am trying not to use global variables unless I have to. I may have to but since I am able to execute the above code, it seems as though I do not need to use a global variable.
As discussed in OP comments, testStr has already been freed.
Is there any way to force the retaining of a variable that has been created in a function? Then release it later?
It's not impossible, but I don't know this is the best way to do that.
Anyway, try this with Playground or OS X "Command Line Tool" template:
import Foundation
func foo() {
var str:NSString = "Hello World"
let ptr = UnsafePointer<Void>(Unmanaged<NSString>.passRetained(str).toOpaque())
bar(ptr)
}
func bar(v:UnsafePointer<Void>) {
let at = dispatch_time(
DISPATCH_TIME_NOW,
Int64(2.0 * Double(NSEC_PER_SEC))
)
dispatch_after(at, dispatch_get_main_queue()) {
baz(v)
}
}
func baz(v:UnsafePointer<Void>) {
println("notified")
let str = Unmanaged<NSString>.fromOpaque(COpaquePointer(v)).takeRetainedValue()
println("info: \(str)")
}
foo()
println("started")
dispatch_main()
Unmanaged<NSString>.passRetained(str) increments the retain count.
Unmanaged<NSString>.fromOpaque(...).takeRetainedValue() decrements it, and extract the object.
I think, using pure Swift String is impossible. because String is struct and is allocated in stack memory. Maybe the buffer of it is allocated in heap, but we cannot access it directly.
I want to know the contents of a Map while debugging a c++ program.
I am using command line dbx.
I have pointer to the map.
Is there a way in which i can get the data printed.
--
Edit:
p *dataMap will give me this::
p *dataMap
*dataMap = {
__t = {
__buffer_size = 32U
__buffer_list = {
__data_ = 0x3ba2b8
}
__free_list = (nil)
__next_avail = 0x474660
__last = 0x474840
__header = 0x3b97b8
__node_count = 76U
__insert_always = false
__key_compare = {
/* try using "print -r" to see any inherited members */
}
}
}
Thanks
Alok Kr.
you need to write a ksh function to pretty print map, here is an example :
put following line in .dbxrc
source /ksh_STL_map
in dbx, use ppp to call ksh function that define in ksh_STL_map:
(dbx) ppp k
k = 2 elems {343, 0x301f8; 565, 0x30208}
I tried to post content of ksh_STL_map here, but this editor format will mess up the content, it's better that you post your email, then I can send ksh_STL_map directly to you.