Question about concatenation error

Collapse
This topic is closed.
X
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • colonel
    #1

    Question about concatenation error

    I am new to python and I am confused as to why when I try to
    concatenate 3 strings, it isn't working properly.

    Here is the code:

    ------------------------------------------------------------------------------------------
    import string
    import sys
    import re
    import urllib

    linkArray = []
    srcArray = []
    website = sys.argv[1]

    urllib.urlretri eve(website, 'getfile.txt')

    filename = "getfile.tx t"
    input = open(filename, 'r')
    reg1 = re.compile('hre f=".*"')
    reg3 = re.compile('".* ?"')
    reg4 = re.compile('htt p')
    Line = input.readline( )

    while Line:
    searchstring1 = reg1.search(Lin e)
    if searchstring1:
    rawlink = searchstring1.g roup()
    link = reg3.search(raw link).group()
    link2 = link.split('"')
    cleanlink = link2[1:2]
    fullink = reg4.search(str (cleanlink))
    if fullink:
    linkArray.appen d(cleanlink)
    else:
    cleanlink2 = str(website) + "/" + str(cleanlink)
    linkArray.appen d(cleanlink2)
    Line = input.readline( )

    print linkArray
    -----------------------------------------------------------------------------------------------

    I get this:

    ["http://www.slugnuts.co m/['index.html']",
    "http://www.slugnuts.co m/['movies.html']",
    "http://www.slugnuts.co m/['ramblings.html ']",
    "http://www.slugnuts.co m/['sluggies.html']",
    "http://www.slugnuts.co m/['movies.html']"]

    instead of this:

    ["http://www.slugnuts.co m/index.html]",
    "http://www.slugnuts.co m/movies.html]",
    "http://www.slugnuts.co m/ramblings.html]",
    "http://www.slugnuts.co m/sluggies.html]",
    "http://www.slugnuts.co m/movies.html]"]

    The concatenation isn't working the way I expected it to. I suspect
    that I am screwing up by mixing types, but I can't see where...

    I would appreciate any advice or pointers.

    Thanks.
    Tags: None
    • colonel
      #2
      Re: Question about concatenation error

      On Wed, 07 Sep 2005 16:34:25 GMT, colonel <thecamel@camel richard.org>
      wrote:
      [color=blue]
      >I am new to python and I am confused as to why when I try to
      >concatenate 3 strings, it isn't working properly.
      >
      >Here is the code:
      >
      >------------------------------------------------------------------------------------------
      >import string
      >import sys
      >import re
      >import urllib
      >
      >linkArray = []
      >srcArray = []
      >website = sys.argv[1]
      >
      >urllib.urlretr ieve(website, 'getfile.txt')
      >
      >filename = "getfile.tx t"
      >input = open(filename, 'r')
      >reg1 = re.compile('hre f=".*"')
      >reg3 = re.compile('".* ?"')
      >reg4 = re.compile('htt p')
      >Line = input.readline( )
      >
      >while Line:
      > searchstring1 = reg1.search(Lin e)
      > if searchstring1:
      > rawlink = searchstring1.g roup()
      > link = reg3.search(raw link).group()
      > link2 = link.split('"')
      > cleanlink = link2[1:2]
      > fullink = reg4.search(str (cleanlink))
      > if fullink:
      > linkArray.appen d(cleanlink)
      > else:
      > cleanlink2 = str(website) + "/" + str(cleanlink)
      > linkArray.appen d(cleanlink2)
      > Line = input.readline( )
      >
      >print linkArray
      >-----------------------------------------------------------------------------------------------
      >
      >I get this:
      >
      >["http://www.slugnuts.co m/['index.html']",
      >"http://www.slugnuts.co m/['movies.html']",
      >"http://www.slugnuts.co m/['ramblings.html ']",
      >"http://www.slugnuts.co m/['sluggies.html']",
      >"http://www.slugnuts.co m/['movies.html']"]
      >
      >instead of this:
      >
      >["http://www.slugnuts.co m/index.html]",
      >"http://www.slugnuts.co m/movies.html]",
      >"http://www.slugnuts.co m/ramblings.html]",
      >"http://www.slugnuts.co m/sluggies.html]",
      >"http://www.slugnuts.co m/movies.html]"]
      >
      >The concatenation isn't working the way I expected it to. I suspect
      >that I am screwing up by mixing types, but I can't see where...
      >
      >I would appreciate any advice or pointers.
      >
      >Thanks.[/color]


      Okay. It works if I change:

      fullink = reg4.search(str (cleanlink))
      if fullink:
      linkArray.appen d(cleanlink)
      else:
      cleanlink2 = str(website) + "/" + str(cleanlink)

      to

      fullink = reg4.search(cle anlink[0])
      if fullink:
      linkArray.appen d(cleanlink[0])
      else:
      cleanlink2 = str(website) + "/" + cleanlink[0]


      so can anyone tell me why "cleanlink" gets coverted to a list? Is it
      during the slicing?


      Thanks.

        Comment

        • Steve Holden
          #3
          Re: Question about concatenation error

          colonel wrote:[color=blue]
          > On Wed, 07 Sep 2005 16:34:25 GMT, colonel <thecamel@camel richard.org>
          > wrote:
          >
          >[color=green]
          >>I am new to python and I am confused as to why when I try to
          >>concatenate 3 strings, it isn't working properly.
          >>
          >>Here is the code:
          >>
          >>------------------------------------------------------------------------------------------
          >>import string
          >>import sys
          >>import re
          >>import urllib
          >>
          >>linkArray = []
          >>srcArray = []
          >>website = sys.argv[1]
          >>
          >>urllib.urlret rieve(website, 'getfile.txt')
          >>
          >>filename = "getfile.tx t"
          >>input = open(filename, 'r')
          >>reg1 = re.compile('hre f=".*"')
          >>reg3 = re.compile('".* ?"')
          >>reg4 = re.compile('htt p')
          >>Line = input.readline( )
          >>
          >>while Line:
          >> searchstring1 = reg1.search(Lin e)
          >> if searchstring1:
          >> rawlink = searchstring1.g roup()
          >> link = reg3.search(raw link).group()
          >> link2 = link.split('"')
          >> cleanlink = link2[1:2]
          >> fullink = reg4.search(str (cleanlink))
          >> if fullink:
          >> linkArray.appen d(cleanlink)
          >> else:
          >> cleanlink2 = str(website) + "/" + str(cleanlink)
          >> linkArray.appen d(cleanlink2)
          >> Line = input.readline( )
          >>
          >>print linkArray
          >>-----------------------------------------------------------------------------------------------
          >>
          >>I get this:
          >>
          >>["http://www.slugnuts.co m/['index.html']",
          >>"http://www.slugnuts.co m/['movies.html']",
          >>"http://www.slugnuts.co m/['ramblings.html ']",
          >>"http://www.slugnuts.co m/['sluggies.html']",
          >>"http://www.slugnuts.co m/['movies.html']"]
          >>
          >>instead of this:
          >>
          >>["http://www.slugnuts.co m/index.html]",
          >>"http://www.slugnuts.co m/movies.html]",
          >>"http://www.slugnuts.co m/ramblings.html]",
          >>"http://www.slugnuts.co m/sluggies.html]",
          >>"http://www.slugnuts.co m/movies.html]"]
          >>
          >>The concatenation isn't working the way I expected it to. I suspect
          >>that I am screwing up by mixing types, but I can't see where...
          >>
          >>I would appreciate any advice or pointers.
          >>
          >>Thanks.[/color]
          >
          >
          >
          > Okay. It works if I change:
          >
          > fullink = reg4.search(str (cleanlink))
          > if fullink:
          > linkArray.appen d(cleanlink)
          > else:
          > cleanlink2 = str(website) + "/" + str(cleanlink)
          >
          > to
          >
          > fullink = reg4.search(cle anlink[0])
          > if fullink:
          > linkArray.appen d(cleanlink[0])
          > else:
          > cleanlink2 = str(website) + "/" + cleanlink[0]
          >
          >
          > so can anyone tell me why "cleanlink" gets coverted to a list? Is it
          > during the slicing?
          >
          >
          > Thanks.[/color]

          The statement

          cleanlink = link2[1:2]

          results in a list of one element. If you want to accesss element one
          (the second in the list) then use

          cleanlink = link2[1]

          regards
          Steve
          --
          Steve Holden +44 150 684 7255 +1 800 494 3119
          Holden Web LLC http://www.holdenweb.com/

            Comment

            • Terry Reedy
              #4
              Re: Question about concatenation error


              "colonel" <thecamel@camel richard.org> wrote in message
              news:cu5uh1h6nu bs7mm0f2fmdc2de 58f9nrq87@4ax.c om...[color=blue]
              > so can anyone tell me why "cleanlink" gets coverted to a list?
              > Is it during the slicing?[/color]

              Steve answered for you, but for next time, you could find out faster by
              either using the all-purpose debuging tool known as 'print' or, with
              Python, the handy-dandy interactive window:[color=blue][color=green][color=darkred]
              >>> [1,2,3][1:2][/color][/color][/color]
              [2]

              Terry J. Reedy



                Comment

                • Terry Hancock
                  #5
                  Re: Question about concatenation error

                  On Wednesday 07 September 2005 11:34 am, colonel wrote:[color=blue]
                  > I am new to python and I am confused as to why when I try to
                  > concatenate 3 strings, it isn't working properly.
                  >
                  > Here is the code:[/color]

                  I'm not taking the time to really study it, but at first
                  glance, the code looks like it's probably much more
                  complicated than it needs to be.
                  [color=blue]
                  > ["http://www.slugnuts.co m/['index.html']",
                  > "http://www.slugnuts.co m/['movies.html']",
                  > "http://www.slugnuts.co m/['ramblings.html ']",
                  > "http://www.slugnuts.co m/['sluggies.html']",
                  > "http://www.slugnuts.co m/['movies.html']"][/color]

                  The tail end of that is the string representation of
                  a list containing one string, not of that string. I
                  suspect you needed to use ''.join() somewhere. Or,
                  you could, in principle have indexed the list, since
                  you only want one member of it, e.g.:
                  [color=blue][color=green][color=darkred]
                  >>> ['index.html'][0][/color][/color][/color]
                  'index.html'

                  --
                  Terry Hancock ( hancock at anansispacework s.com )
                  Anansi Spaceworks http://www.anansispaceworks.com

                    Comment

                    Previous template Next
                    Working...