Develop Reference

Writing to named pipe - Errno 22 in Pycharm only

I'm trying to send commands to Audacity using a named pipe, which can be tested using: (https://github.com/audacity/audacity/blob/master/scripts/piped-work/pipe_test.py provided by Audacity)
import os
import sys
if sys.platform == 'win32':
print("pipe-test.py, running on windows")
TONAME = '\\\\.\\pipe\\ToSrvPipe'
FROMNAME = '\\\\.\\pipe\\FromSrvPipe'
EOL = '\r\n\0'
else:
print("pipe-test.py, running on linux or mac")
TONAME = '/tmp/audacity_script_pipe.to.' + str(os.getuid())
FROMNAME = '/tmp/audacity_script_pipe.from.' + str(os.getuid())
EOL = '\n'
print("Write to \"" + TONAME +"\"")
if not os.path.exists(TONAME):
print(" ..does not exist. Ensure Audacity is running with mod-script-pipe.")
sys.exit()
print("Read from \"" + FROMNAME +"\"")
if not os.path.exists(FROMNAME):
print(" ..does not exist. Ensure Audacity is running with mod-script-pipe.")
sys.exit()
print("-- Both pipes exist. Good.")
TOFILE = open(TONAME, 'w')
print("-- File to write to has been opened")
FROMFILE = open(FROMNAME, 'rt')
print("-- File to read from has now been opened too\r\n")
On a first run, with Audacity open, this yields:
pipe-test.py, running on windows
Traceback (most recent call last):
Write to "\\.\pipe\ToSrvPipe"
Read from "\\.\pipe\FromSrvPipe"
File "C:/Users/chris/PycharmProjects/Youtube-Spotify-DL/pipe_test3.py", line 44, in <module>
-- Both pipes exist. Good.
TOFILE = open(TONAME, 'w')
OSError: [Errno 22] Invalid argument: '\\\\.\\pipe\\ToSrvPipe'
Process finished with exit code 1
On a second run:
Traceback (most recent call last):
File "C:/Users/chris/PycharmProjects/Youtube-Spotify-DL/pipe_test3.py", line 44, in <module>
pipe-test.py, running on windows
TOFILE = open(TONAME, 'w')
FileNotFoundError: [Errno 2] No such file or directory: '\\\\.\\pipe\\ToSrvPipe'
Write to "\\.\pipe\ToSrvPipe"
Read from "\\.\pipe\FromSrvPipe"
-- Both pipes exist. Good.
Process finished with exit code 1
So it seems like the pipe cannot be written to and/or closes. However, when running this script through IDLE, it runs just fine. So, in what way is Pycharm preventing writing to this named pipe, and how could it be fixed?
Thanks.

Did you open audacity before running the test script? Audacity needs to run

Running python subprocess.call on tgz file to untar and stream output

I'm using a subprocess call to untar a file in the command line, I need to use the output of that call to stream into a temp file so I can read the contents of the "+CONTENTS" folder with in the tgz file.
My failed output is:
./streamContents.py
rsh: ftp: No address associated with hostname
tar (child): ftp://myftpserver.com/pkgsrc/doxygen_pkgs/test.
tgz: Cannot open: Input/output error
tar (child): Error is not recoverable: exiting now
gzip: stdin: unexpected end of file
tar: Child returned status 2
tar: Error exit delayed from previous errors
Traceback (most recent call last):
File "./streamContents.py", line 29, in
stream = proc.stdout.read(8196)
AttributeError: 'int' object has no attribute 'stdout'
#!/usr/bin/python
from io import BytesIO
import urllib2
import tarfile
import ftplib
import socket
import threading
import subprocess
tarfile_url = "ftp://myftpserver.com/pkgsrc/doxygen_pkgs/test.tg
z"
try:
ftpstream = urllib2.urlopen(tarfile_url)
except URLerror, e:
print "URL timeout"
except socket.timeout:
print "Socket timeout"
# BytesIO creates an in-memory temporary file.
tmpfile = BytesIO()
last_size = 0
tfile_extract = ""
while True:
proc = subprocess.call(['tar','-xzvf', tarfile_url], stdout=subprocess.PIPE)
# Download a piece of the file from the ftp connection
stream = proc.stdout.read(8196)
if not stream: break
tmpfile.write(bytes(stream))
# Seeking back to the beginning of the temporary file.
tmpfile.seek(0)
# r|gz forbids seeking backward; r:gz allows seeking backward
try:
tfile = tarfile.open(fileobj=tmpfile, mode="r:gz")
print tfile.extractfile("+CONTENTS")
tfile_extract_text = tfile_extract.read()
print tfile_extract.tell()
tfile.close()
if tfile_extract.tell() > 0 and tfile_extract.tell() == last_size:
print tfile_extract_text
break
else:
last_size = tfile_extract.tell()
except Exception:
tfile.close()
pass
tfile_extract_text = tfile_extract.read()
print tfile_extract_text
# When you're done:
tfile.close()
tmpfile.close()

Expanding on my comment above, you need to do download the tar file using urllib2 and tempfile to a temporary file and then open this temporary file using tarfile.
Here's some code to get started:
import urllib2
import tarfile
from tempfile import TemporaryFile
f_url = 'url_of_your_tar_archive'
ftpstream = urllib2.urlopen(f_url)
tmpfile = TemporaryFile()
# Download contents of tar to a temporary file
while True:
s = ftpstream.read(16384)
if not s:
break
tmpfile.write(s)
ftpstream.close()
# Access the temporary file to extract the file you need
tmpfile.seek(0)
tfile = tarfile.open(fileobj=tmpfile, mode='r:gz')
print tfile.getnames()
contents = tfile.extractfile("+CONTENTS").read()
print contents

.xlsx and xls(Latest Versions) to pdf using python

With the help of this .doc to pdf using python
Link I am trying for excel (.xlsx and xls formats)
Following is modified Code for Excel:
import os
from win32com import client
folder = "C:\\Oprance\\Excel\\XlsxWriter-0.5.1"
file_type = 'xlsx'
out_folder = folder + "\\PDF_excel"
os.chdir(folder)
if not os.path.exists(out_folder):
print 'Creating output folder...'
os.makedirs(out_folder)
print out_folder, 'created.'
else:
print out_folder, 'already exists.\n'
for files in os.listdir("."):
if files.endswith(".xlsx"):
print files
print '\n\n'
word = client.DispatchEx("Excel.Application")
for files in os.listdir("."):
if files.endswith(".xlsx") or files.endswith('xls'):
out_name = files.replace(file_type, r"pdf")
in_file = os.path.abspath(folder + "\\" + files)
out_file = os.path.abspath(out_folder + "\\" + out_name)
doc = word.Workbooks.Open(in_file)
print 'Exporting', out_file
doc.SaveAs(out_file, FileFormat=56)
doc.Close()
It is showing following error :
>>> execfile('excel_to_pdf.py')
Creating output folder...
C:\Excel\XlsxWriter-0.5.1\PDF_excel created.
apms_trial.xlsx
~$apms_trial.xlsx
Exporting C:\Excel\XlsxWriter-0.5.1\PDF_excel\apms_trial.pdf
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "excel_to_pdf.py", line 30, in <module>
doc = word.Workbooks.Open(in_file)
File "<COMObject <unknown>>", line 8, in Open
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, u'Microsoft Excel
', u"Excel cannot open the file '~$apms_trial.xlsx' because the file format or f
ile extension is not valid. Verify that the file has not been corrupted and that
the file extension matches the format of the file.", u'xlmain11.chm', 0, -21468
27284), None)
>>>
There is problem in
doc.SaveAs(out_file, FileFormat=56)
What should be FileFormat file format?
Please Help

Link of xlsxwriter :
https://xlsxwriter.readthedocs.org/en/latest/contents.html
With the help of this you can generate excel file with .xlsx and .xls
for example excel file generated name is trial.xls
Now if you want to generate pdf of that excel file then do the following :
from win32com import client
xlApp = client.Dispatch("Excel.Application")
books = xlApp.Workbooks.Open('C:\\excel\\trial.xls')
ws = books.Worksheets[0]
ws.Visible = 1
ws.ExportAsFixedFormat(0, 'C:\\excel\\trial.pdf')

I got the same thing and the same error... ANSWER: 57.... see below...
from win32com import client
import win32api
def exceltopdf(doc):
excel = client.DispatchEx("Excel.Application")
excel.Visible = 0
wb = excel.Workbooks.Open(doc)
ws = wb.Worksheets[1]
try:
wb.SaveAs('c:\\targetfolder\\result.pdf', FileFormat=57)
except Exception, e:
print "Failed to convert"
print str(e)
finally:
wb.Close()
excel.Quit()
... as an alternative to the fragile ExportAsFixedFormat...

You can print an excel sheet to pdf on linux using python.
Do need to run openoffice as a headless server and use unoconv, takes a bit of configuring but is doable
You run OO as a (service) daemon and use it for the conversions for xls, xlsx and doc, docx.
http://dag.wiee.rs/home-made/unoconv/

Another solution for
Is to start gotenberg docker container locally
https://github.com/gotenberg/gotenberg
And pass (any supported by libreoffice) file from python wia HTTP to the container and get result as pdf
LIBREOFFICE_URL = 'http://localhost:3000/forms/libreoffice/convert'
LIBREOFFICE_LANDSCAPE_URL = 'http://localhost:3000/forms/libreoffice/convert?landscape=1'
def _retry_gotenberg(url, io_bytes, post_file_name='index.html'):
response = None
for _ in range(5):
response = requests.post(url, files={post_file_name: io_bytes})
if response.status_code == 200:
break
logging.info('Will sleep and retry: %s %s', response.status_code, response.content)
sleep(3)
if not response or response.status_code != 200:
raise RuntimeRrror(f'Bad response from doc-to-pdf: {response.status_code} {response.content}')
return response
def process_libreoffice(io_bytes, ext: str):
if ext in ('.doc', '.docx'):
url = LIBREOFFICE_URL
else:
url = LIBREOFFICE_LANDSCAPE_URL
response = self._retry_gotenberg(url, io_bytes, post_file_name=f'file.{ext}')
return response.content

The GroupDocs.Conversion Cloud SDK for Python is another option to convert Excel to PDF. It is paid API. However, it provides 150 free monthly API calls.
P.S: I'm a developer evangelist at GroupDocs.
# Import module
import groupdocs_conversion_cloud
from shutil import copyfile
# Get your client_id and client_key at https://dashboard.groupdocs.cloud (free registration is required).
client_id = "xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxx"
client_key = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
# Create instance of the API
convert_api = groupdocs_conversion_cloud.ConvertApi.from_keys(client_id, client_key)
try:
#Convert PDF to PNG
# Prepare request
request = groupdocs_conversion_cloud.ConvertDocumentDirectRequest("pdf", "C:/Temp/Book1.xlsx")
# Convert
result = convert_api.convert_document_direct(request)
copyfile(result, 'C:/Temp/Book1_output.pdf')
print("Result {}".format(result))
except groupdocs_conversion_cloud.ApiException as e:
print("Exception when calling get_supported_conversion_types: {0}".format(e.message))

Python ftplib file open() TypeError

I am trying to upload a file to an ftp server with python using the ftplib.
This is what i have:
def ftp(cmd):
cmd = cmd.split(' ')
try: cmd[3]
except: return 'host user password file (ftpdir)'
try: session = ftplib.FTP(cmd[0],cmd[1],cmd[2])
except: return 'wrong credentials/host'
try: file = open(cmd[3], 'rb')
except: return 'unable to reach file'
try: cmd[4]
except: pass
else:
if cmd[4] !='':
ftplib.FTP.cwd(ftpdir)
name = file.split('\\')[-1]
session.storbinary('STOR ' + name, file) # send the file
file.close() # close file and FTP
session.quit()
I give the function a command in the form of 'host user password file ftpdir' where ftpdir is not required. The error I get is this one:
Traceback (most recent call last):
...some lines of referring...
File "C:\somedir\somefile.py", line 155, in ftp
file = open(cmd[3],'rb')
TypeError: open() takes exactly 1 argument (2 given)
If i try the command "file = open(cmd[3], 'rb')" with a given 'cmd' as entry in a python shell it works fine.

This question is now answered. The problem was that I defined another function open(arg) which took exactely one argument. After changing the name of that function, everything worked fine.
Thank you for your time everyone who read this.

display an error message when file is empty - proper way?

hi im slowly trying to learn the correct way to write python code. suppose i have a text file which i want to check if empty, what i want to happen is that the program immediately terminates and the console window displays an error message if indeed empty. so far what ive done is written below. please teach me the proper method on how one ought to handle this case:
import os
def main():
f1name = 'f1.txt'
f1Cont = open(f1name,'r')
if not f1Cont:
print '%s is an empty file' %f1name
os.system ('pause')
#other code
if __name__ == '__main__':
main()

There is no need to open() the file, just use os.stat().
>>> #create an empty file
>>> f=open('testfile','w')
>>> f.close()
>>> #open the empty file in read mode to prove that it doesn't raise IOError
>>> f=open('testfile','r')
>>> f.close()
>>> #get the size of the file
>>> import os
>>> import stat
>>> os.stat('testfile')[stat.ST_SIZE]
0L
>>>

The pythonic way to do this is:
try:
f = open(f1name, 'r')
except IOError as e:
# you can print the error here, e.g.
print(str(e))

Maybe a duplicate of this.
From the original answer:
import os
if (os.stat(f1name).st_size == 0)
print 'File is empty!'

If file open succeeds the value of 'f1Cont` will be a file object and will not be False (even if the file is empty).One way you can check if the file is empty (after a successful open) is :
if f1Cont.readlines():
print 'File is not empty'
else:
print 'File is empty'

Assuming you are going to read the file if it has data in it, I'd recommend opening it in append-update mode and seeing if the file position is zero. If so, there's no data in the file. Otherwise, we can read it.
with open("filename", "a+") as f:
if f.tell():
f.seek(0)
for line in f: # read the file
print line.rstrip()
else:
print "no data in file"

one can create a custom exception and handle that using a try and except block as below
class ContentNotFoundError(Exception):
pass
with open('your_filename','r') as f:
try:
content=f.read()
if not content:
raise ContentNotFoundError()
except ContentNotFoundError:
print("the file you are trying to open has no contents in it")
else:
print("content found")
print(content)
This code will print the content of the file given if found otherwise will print the message
the file you are trying to open has no contents in it