file doesn't exist

[mcgrim]

I am trying to display an image through socket programming,
I have a server and a client file, and they seem to run fine,
however, once I write my file in the console (see input command),
I always obtain the message 'file doesn't exist'.
I am not sure why, because the files I use are in the same directory as
the python files.
Any ideas?

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#SERVER import socket import threading import os   from idlelib.iomenu import encoding     def retrieve_file(name, sock):     filename=sock.recv(1024)     if os.path.isfile(filename):         sock.send( ("EXISTS" + str(os.path.getsize(filename))).encode(encoding) )         user_response = sock.recv(1024)         if user_response[:2] == 'OK':             with open(filename, 'rb') as f:                 send_bytes=f.read(1024)                 sock.send(send_bytes)                 while send_bytes !='':                     send_bytes= f.read(1024)                     sock.send(send_bytes)     else:         sock.send(b"error, file does not exist")     sock.close()     def Main():     host = "127.0.0.1"     port = 5000       s=socket.socket()     s.bind((host,port))       s.listen(5)       print("server started...")       while True:         c, addr= s.accept()         print("client connected ip>:" + str(addr))         t=threading.Thread(target=retrieve_file, args=("retrThread",c))         t.start()       s.close()   if __name__ == '__main__':     Main()

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#CLIENT   import socket   def Main():     host = "127.0.0.1"     port = 5000       s=socket.socket()     s.connect((host,port))         filename= input("enter file name ->")     if filename != 'q':         s.send(filename.encode())         data= s.recv(1024)         if data[:6] == 'EXISTS':             filesize = int(data[:6])             message= input("this file exists " + str(filesize) + "bytes, download(Y/N)?")             if message == 'Y':                 s.send('OK')                 f=open(filesize, 'wb')                 data=s.recv(1024)                 total_received=len(data)                 f.write(data)                 while total_received < filesize:                     data=s.recv(1024)                     total_received += len(data)                     f.write(data)                 print("download complete")           else:             print("file doesn't exist")     s.close()     if __name__ == '__main__':     Main()

[Larz60+]

I always obtain the message 'file doesn't exist'.

Always show the entire error traceback, verbatim

I am not sure why, because the files I use are in the same directory as
the python files

The current working directory may not be the same as the src directory, to assure this is the case, add the following statement as the first line executed:

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# add import import os   #add as first line executed (in front of line 6) os.chdir(os.path.abspath(os.path.dirname(__file__)))

[mcgrim]

I did what you said, by adding that line,
but I still get the same outcome.

this is the server output

Output:
C:\Users\\PycharmProjects\client-server\venv\Scripts\python.exe C:/Users//PycharmProjects/client-server/server_2.py
server started...
client connected ip>:('127.0.0.1', 59653)

and this is the client output

Output:
C:\Users\PycharmProjects\client-server\venv\Scripts\python.exe C:/Users/PycharmProjects/client-server/client_2.py
enter file name ->upper.txt
file doesn't exist

Process finished with exit code 0

[Gribouillis]

Try to get more information, replace print("file doesn't exist") with

1	print("file doesn't exist, got:", repr(data))

[mcgrim]

this is the outcome that I have now, but I am not sure what this means.

Output:
C:\Users\PycharmProjects\client-server\venv\Scripts\python.exe C:/Users/PycharmProjects/client-server/client_2.py
enter file name ->upper.txt
file doesn't exist, got: b'EXISTS18'

Process finished with exit code 0

[buran]

data is byte string
you need to compare it with b'EXISTS' on line 17:

1	if data[:6] == b'EXISTS':

or decode data:

1	if data[:6].decode() == 'EXISTS':

also as per PEP8 it's better to use startswith:

1	if data.decode().startswith('EXISTS'):

[mcgrim]

I changed line 16 and got this error.
Also, what do you mean by PEP8 ?
which line are you referring to?

Error:
enter file name ->upper.txt
Traceback (most recent call last):
  File "C:/Users/PycharmProjects/client-server/client_2.py", line 36, in <module>
    Main()
  File "C:/Users/PycharmProjects/client-server/client_2.py", line 16, in Main
    filesize = int(data[:6])
ValueError: invalid literal for int() with base 10: b'EXISTS'

Process finished with exit code 1

[buran]

I changed line 16 and got this error.

why would you change it?

which line are you referring to?

As i said - line 17, in CLIENT code. Currently it reads:

1	if data[:6] == 'EXISTS':

Also, what do you mean by PEP8 ?

https://www.python.org/dev/peps/pep-0008...mendations

Use ''.startswith() and ''.endswith() instead of string slicing to check for prefixes or suffixes.

startswith() and endswith() are cleaner and less error prone:

1 2	Yes: if foo.startswith('bar'): No:  if foo[:3] == 'bar':

[mcgrim]

I meant line 17 before,
however, I changed that line from

1	if data[:6] == 'EXISTS':

to

1	if data.decode().startswith('EXISTS'):

and got this error

Error:
enter file name ->upper.txt
Traceback (most recent call last):
  File "C:/Users//PycharmProjects/client-server/client_2.py", line 37, in <module>
    Main()
  File "C:/Users//PycharmProjects/client-server/client_2.py", line 17, in Main
    filesize = int(data[:6]).encode()
ValueError: invalid literal for int() with base 10: b'EXISTS'

Process finished with exit code 1

[buran]

obviously first 6 chars are EXISTS, so how you expect it to be int?
replace

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data= s.recv(1024) if data[:6] == 'EXISTS':     filesize = int(data[:6])

with

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data= s.recv(1024) data = data.decode() if data.startswith('EXISTS'):     filesize = int(data[6:])

or

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data= s.recv(1024) if data.startswith(b'EXISTS'):     filesize = int(data[6:])