[Tutor] lxml.html

Steven D'Aprano steve at pearwood.info
Wed Jun 8 17:36:44 CEST 2011


nitin chandra wrote:
> Hello Every One,
> 
>          doc = lxml.html.parse('/home/dev/wsgi-scripts/index.py').getroot()
>          name = doc.forms[0].fields['name']
> 
>          html = 'name is '
>          html += name
> 
> ERROR
> [Wed Jun 08 20:29:51 2011] [error] [client 192.168.1.9] Traceback
> (most recent call last):

What is all this extraneous date/error/ip address nonsense in the 
traceback? Where does it come from?

> TypeError:
> cannot concatenate 'str' and 'NoneType' objects

> I am extracting form field name / value from an html, but then it
> gives the above error and does
> not display the value of the variable 'name' entered in the respective form.

What is the value of the variable 'name'?

Hint: read the error message that you get when you try to concatenate a 
string with the None object:
 >>> "spam" + None
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'NoneType' objects




-- 
Steven


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