Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trial
Rajesh Tupakula
1,927 PointsNeed help with the regular expression.
when I use this below script it complains about the string pattern
import urllib.request
import re
from re import findall
page = urllib.request.urlopen('https://sonar.com/prod/drilldown/measures/1274530?metric=coverage')
data = page.read()
print(page.read())
html = page.read()
htmlStr = html.decode()
print(data)
print(re.findall(r'[coverag]{8}', data))
Traceback (most recent call last):
File "C:\Users\a530614\Documents\pythons\script.py", line 10, in <module>
print(re.findall(r'\b[coverag]\b', data))
File "C:\Users\a530614\python\lib\re.py", line 213, in findall
return _compile(pattern, flags).findall(string)
TypeError: cannot use a string pattern on a bytes-like object
but when use b type it works for me.
import urllib.request
import re
from re import findall
page = urllib.request.urlopen('https://sonar.com/prod/drilldown/measures/1274530?metric=coverage')
data = page.read()
print(page.read())
html = page.read()
htmlStr = html.decode()
print(data)
print(re.findall(b'[coverag]{8}', data))
What is that I am missing here ?
[MOD: added ``` markdown formatting -cf]
1 Answer
Chris Freeman
Treehouse Moderator 68,423 Pointsurllib.request.urlopen returns an HTTPResonse object. The .read() method returns a bytes object. Looking at it interactively:
$ python3
Python 3.4.3 (default, Oct 14 2015, 20:28:29)
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib.request
# Get page
>>> page = urllib.request.urlopen('https://teamtreehouse.com/')
>>> type(page)
<class 'http.client.HTTPResponse'>
# Get data
>>> data = page.read()
>>> type(data)
<class 'bytes'>
A bytes object is different from a string object. Using re on a bytes object requires a bytes regex. The "b" signifies that the string should be interpreted as bytes. You can also pair this with the "r" to signify a raw-bytes pattern.
# Using data from above
>>> import re
>>> re.findall(b'Treehouse', data)
[b'Treehouse', b'Treehouse', b'Treehouse', b'Treehouse', b'Treehouse', b'Treehouse']
# Try again with regular string will Fail
>>> re.findall('Treehouse', data)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.4/re.py", line 210, in findall
return _compile(pattern, flags).findall(string)
TypeError: can't use a string pattern on a bytes-like object
Post back if you have if you need more help.
Chris Freeman
Treehouse Moderator 68,423 PointsChris Freeman
Treehouse Moderator 68,423 PointsWhy was this down voted? Was there an issue with this answer?