Question about concatenation error

[colonel]

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.urlretrieve(website, 'getfile.txt')

filename = "getfile.txt"
input = open(filename, 'r')
reg1 = re.compile('href=".*"')
reg3 = re.compile('".*?"')
reg4 = re.compile('http')
Line = input.readline()

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

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

I get this:

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

instead of this:

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

 

[colonel]

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.urlretrieve(website, 'getfile.txt')

filename = "getfile.txt"
input = open(filename, 'r')
reg1 = re.compile('href=".*"')
reg3 = re.compile('".*?"')
reg4 = re.compile('http')
Line = input.readline()

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

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

I get this:

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

instead of this:

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

Okay. It works if I change:

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

to

fullink = reg4.search(cleanlink[0])
if fullink:
linkArray.append(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.

 

[Steve Holden]

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.urlretrieve(website, 'getfile.txt')

filename = "getfile.txt"
input = open(filename, 'r')
reg1 = re.compile('href=".*"')
reg3 = re.compile('".*?"')
reg4 = re.compile('http')
Line = input.readline()

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

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

I get this:

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

instead of this:

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

Okay. It works if I change:

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

to

fullink = reg4.search(cleanlink[0])
if fullink:
linkArray.append(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.

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

 

[Terry Reedy]

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

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:

[1,2,3][1:2]

[2]

Terry J. Reedy

 

[Terry Hancock]

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:

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.

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

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.:

['index.html'][0]

'index.html'