I have been trying to read a jpeg file using PIL in python 3.4. I need to save this file into string format. Although some options are provided on this site but I have tried a few but it is not working. Following is my code snippet which i have found on this site only:-
from io import StringIO
fp = Image.open("images/login.jpg")
output = StringIO()
fp.save(output, format="JPEG")
contents = output.getvalue()
output.close()
But i am facing the following error :-
TypeError: string argument expected, got 'bytes'
Could you please suggest what I have done wrong and how to get this working?
In python 3 you should use a BytesIO,
whereas as read in python docs:
StringIO is a native in-memory unicode container
.
Thanks a lot for the hint. I Actually have a found a different way of reading the image file and storing in string object in python2.x . Here is the code. Please let me know if there is any disadvantage of using this.
imgText = open("images/login.jpg", 'rb')
imgTextStr = imgText.read()
imgText.close()
Related
I am trying to open a file in Colab that uses gb-2312 encoding. Here is the code I successfully ran in my IDE to read and decode:
file = open(r'file.txt')
opened = file.read()
decoded = opened.encode('latin1').decode('gb2312')
print(decoded)
When I run this code in colab, I get the following error:
'utf-8' codec can't decode byte 0xc6 in position 67: invalid continuation byte
But I can't decode without using read() or list() first, or else I get the following error:
'_io.TextIOWrapper' object has no attribute 'encode'
This seems like a catch-22. Is this a bug with Colab or is there some better way to approach the problem?
The default when opening a file is rt (read, text mode) and uses an OS-specific default encoding returned by locale.getpreferredencoding(False). Use the encoding parameter to override the default (which appears to be utf-8):
with open('file.txt', encoding='gb2312') as file:
data = file.read()
I'm trying to setup a .py plugin that will save decoded Protobuf responses to file, but whatever I do, the result is always file in byte format (not decoded). I have also tried to do the same by using "w" in Mitmproxy - although on screen I saw decoded data, in the file it was encoded again.
Any thoughts how to do it correctly?
Sample code for now:
import mitmproxy
def response(flow):
# if flow.request.pretty_url.endswith("some-url.com/endpoint"):
if flow.request.pretty_url.endswith("some-url.com/endpoint"):
f = open("test.log","ab")
with decoded(flow.response)
f.write(flow.request.content)
f.write(flow.response.content)
Eh, I'm not sure this helps, but what happens if you don't open the file in binary mode
f = open("test.log","a")
?
Hy,
some basic things that I found.
Try replacing
f.write(flow.request.content)
with
f.write(flow.request.text)
I read it on this website
https://discourse.mitmproxy.org/t/modifying-https-response-body-not-working/645/3
Please read and try this to get the requests and responses assembled.
MITM Proxy, getting entire request and response string
Best of luck with your project.
I was able to find the way to do that. Seems mitmdump or mitmproxy wasn't able to save raw decoded Protobuf, so I used:
mitmdump -s decode_script.py
with the following script to save the decoded data to a file:
import mitmproxy
import subprocess
import time
def response(flow):
if flow.request.pretty_url.endswith("HERE/IS/SOME/API/PATH"):
protobuffedResponse=flow.response.content
(out, err) = subprocess.Popen(['protoc', '--decode_raw'], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate(protobuffedResponse)
outStr = str(out, 'utf-8')
outStr = outStr.replace('\\"', '"')
timestr = time.strftime("%Y%m%d-%H%M%S")
with open("decoded_messages/" + timestr + ".decode_raw.log","w") as f:
f.write(outStr)
I have problems reading a large JSON file (2.9GB) in Ruby. I am using this code
json_file = File.read(filename)
results = JSON.parse(json_file)
and when I try to read the file I get the error:
Errno::EINVAL: Invalid argument - <filename>
I have tested the same code with smaller files and it works fine. To verify that the file is written correctly I have tried to read it with python and it works.
Is there a limitation on the size of the file for JSON.parse? If so, could you recommend an alternative?
I have looked in the msgpack to reduce the size of the files, but unfortunately I am constraint by the fact that I cannot install gems.
This is a limitation of IO.read.
You may split your file into smaller parts (for example, 1 gigabyte) and read them separately:
dirname = File.dirname(filename)
`split -b 1024m #{filename} #{filename}.parts.`
Dir.chdir(dirname)
parts = Dir["#{filename}.parts.*"]
json = ''
parts.each do |partname|
json += File.read(partname)
File.delete(partname)
end
results = JSON.parse(json)
Be patient, this could take a while.
How do I convert a data URI that comes from the result of the FileReader API into an image file that can be saved in the file system in Ruby?
What I'm currently trying to do is using base64 decode to convert the data_uri string which looks like this: data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEAYABgA... into base 64 encoded string because according to this stackoverflow answer I need to replace all the instances of spaces into +. The answer is in PHP but I'm currently working on Ruby and Sinatra so I'm not sure if it still applies, but when using the equivalent code:
src = data_uri.gsub! ' ', '+'
src = Base64.decode64(src)
f = File.new('uploads/' + 'sample.png', "w")
f.write(src)
f.close
I get the following error:
undefined method `unpack' for nil:NilClass
What I'm trying to achieve here is to be able to convert the data URI to a file.
There's no need to reinvent the wheel. Use the data_uri gem.
require 'data_uri'
uri = URI::Data.new('data:image/gif;base64,...')
File.write('uploads/file.jpg', uri.data)
I'm trying to read a pgm file in R. I set my wd to where the image is and then simply try to read it:
setwd("~/3 Diplomado/5 Multivariado/lfwcrop_grey/faces")
library(pixmap)
x <- read.pnm(system.file("Aaron_Guiel_0001.pgm", package="pixmap")[1])
But I get the following error:
Error in if (ch == "#") { : argument is of length zero
In addition: Warning message:
In file(file, open = "rb") :
file("") only supports open = "w+" and open = "w+b": using the former
Not sure what it is. I think it simply doesnt find the image.
What am I doing wrong? any hints? Thank you in advanced!
J.
Simply try this one:
x=read.pnm(file = "Aaron_Guiel_0001.pgm")
The system.file() is used to find the full path of the files included in packages. It is used in the package example, but you don't need to use it while reading your own file.