Jython not finding file when using variable to pass file name

Question

So heres the issue guys,

I have a very simple little program that reads in some setup details from a file (to make it reuseable for other sets of data) and stores them into variables.

It then uses one of those variables to open another file that I need to write some results to, as well as various search parameters.

When passing the variable to the .open() function, it fails saying it cant find the file, but when passing the exact same information, but as a written string instead of a variable, it works.

Is this a known problem, or am I just doing something wrong?

The code(problem bit bolded)

def urlTrawl(filename):
  import urllib
  read = open(getMediaPath(filename), "rt")
  baseurl = read.readline()
  orgurl = read.readline()
  lasturlfile = read.readline()
  linksfile = read.readline()
  read.close()
  webpage = ""
  links = ""
  counter = 0
  lasturl = ""
  nexturl = ""
  url = ""
  connection = ""
  try:
    read = open(lasturlfile, "rt")
    lasturl = read.readline()
  except IOError:
    print "IOError"

  webpage = connection.read()
  connection.close()
  **file = open(linksfile, "wt")**

  file.close()
  file = open(lasturlfile, "wt")
  file.write(nexturl)
  return 1

The information being passed in

http://www.questionablecontent.net/
http://www.questionablecontent.net/view.php?comic=2480
C:\\Users\\James\\Desktop\\comics\\qclast.txt
C:\\Users\\James\\Desktop\\comics\\comiclinksqc.txt
strip\"
src=\"
\"
Pevious
Next
f=\"
\"

EDIT: removed working code, to narrow down the problem area and updated code to use a direct reference rather then a relative one.

It looks like your path names a relative to the current directory. When you pass in the string, are you using the same relative path? Is the current directory the same in both cases? You might want to consider trying to reduce this code to an SSCCE. It looks like you have some defined functions that aren't included above, and that's a pretty hefty piece of code. One more thing: getMediaPath(filename). Are you sure getMediaPath is working correctly? — jpmc26
– jpmc26, Commented Jul 13, 2013 at 7:31
yes, as I used setMediaPath to set the path for my ide earlier. The reason I find it strange is that I if i say file = open(getMediaPath("comiclinksqc.txt"), "wt") it works, but using the variable that holds this value doesnt. I have also changed it to use full path references rather then getMediaPath(), still not working. — James Sunderland
– James Sunderland, Commented Jul 13, 2013 at 23:46

James Sunderland · Accepted Answer · 2013-07-15 06:34:20Z

2

I found the problem in the end.

The problem was that it was reading in the \n at the end of each line in my details file, and of course the \n isn't anywhere in the website data I'm reading. Removing the last character of each read did the trick:

baseurl = baseurl[:-1]
orgurl = orgurl[:-1]
lasturlfile = lasturlfile[:-1]
linksfile = linksfile[:-1]
search1 = search1[:-1]
search2 = search2[:-1]
search3 = search3[:-1]
search4 = search4[:-1]
search5 = search5[:-1]
search6 = search6[:-1]

answered Jul 15, 2013 at 6:34

James Sunderland

1351 gold badge1 silver badge13 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

jpmc26 Over a year ago

A more robust solution might be to use strip. This would also account for spaces or tabs at the beginning or end of the line, making your file format more flexible. If you're concerned about a file name including whitespace at the end or relative paths where the folder name begins with whitespace, then limit the strip to newline characters: baseurl.strip('\n\r').

jpmc26 · Accepted Answer · 2013-07-14 21:16:36Z

I might not be right, but I think this is what's happening.

You're saying this works fine:

file = open('C:\\Users\\James\\Desktop\\comics\\comiclinksqc.txt', "wt")

But this doesn't:

# After reading three lines
linksfile = read.readline()
file = open(linksfile, "wt")

There is a difference between these two. In the first piece of code, the double slashes are escapes. They resolve to single slashes when Python is done parsing. Like so:

>>> print 'C:\\Users\\James\\Desktop\\comics\\comiclinksqc.txt'
C:\Users\James\Desktop\comics\comiclinksqc.txt

But when you read that same text from the file, there's no parsing of the text. That means that the string stored in your variable still has double slashes.

Try this command out. I bet it fails the same way as when you read the file path in:

file = open(r'C:\\Users\\James\\Desktop\\comics\\comiclinksqc.txt', "wt")

The r stands for "raw"; it prevents Python from interpreting escape characters. If it does fail the same way, then the double slashes are your problem. To fix it, in your file, you need to remove the double slashes:

C:\Users\James\Desktop\comics\comiclinksqc.txt

This isn't a problem in CPython 2.7; I'm betting it's not in 3.x, either. CPython interprets double slashes in some manner that they are effectively a single slash (in most cases, at least). So this may be an issue specific to Jython.

If unclean paths cause errors, you might want to consider doing something to clean them up. os.path.abspath might be helpful, although I can't say if Jython's implementation works as well as CPython's:

>>> print os.path.abspath(r'C:\\Users\\James\\Desktop\\comics\\comiclinksqc.txt')
C:\Users\James\Desktop\comics\comiclinksqc.txt
>>> print os.path.abspath(r'C:/Users/James/Desktop/comics/comiclinksqc.txt')
C:\Users\James\Desktop\comics\comiclinksqc.txt

Thank you for the detailed response, however, file = open(r'C:\\Users\\James\\Desktop\\comics\\comiclinksqc.txt', "wt") did work and after proceeding to work, I shut it down, and checked my links file, and it seems to have bad data in it afterward, meaning the program isn't reading in my search parameters properly either.

mikdiet · Accepted Answer · 2014-06-08 08:54:51Z

0

I am trying to create a script which will list the datasource name and will show the connection pool utilization(pooled connection, Free Pool Size ext.) But facing the issue when list the connection pool, if the data source name having space in between the name like "Default Datasource" then it is listing list "Default Datasource and it is not parsing the datasource name correctly to the next function.

datasource = AdminConfig.list('DataSource', AdminConfig.getid( '/Cell:' 
+ cell + '/')).splitlines()                                             
for datasourceID in datasource:                                         
        datasourceName = datasourceID.split('(')[0]                     
        print datasourceName

Request you to help if possible drop me mail at [email protected] Regards, Bubul

edited Jun 8, 2014 at 8:54

mikdiet

10.1k8 gold badges62 silver badges71 bronze badges

answered Jun 8, 2014 at 8:17

user148607

1

1 Comment

JJJ Over a year ago

Welcome to Stack Overflow! Unlike in discussion forums, you shouldn't post to an existing question if you're having a similar problem. The Ask Question link in the upper right corner can be used to ask new questions. When asking a new question you can link to other posts and explain why they didn't solve the problem in your case. When asking the question don't include your email address. This is not the correct place to request for a personal tutor.

Collectives™ on Stack Overflow

Jython not finding file when using variable to pass file name

3 Answers 3

1 Comment

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related