What am I doing wrong here?
import re
x = "The sky is red"
r = re.compile ("red")
y = r.sub(x, "blue")
print x # Prints "The sky is red"
print y # Prints "blue"
How do i get it to print "The sky is blue"?
Add a comment
|
5 Answers
The problem with your code is that there are two sub functions in the re module. One is the general one and there's one tied to regular expression objects. Your code is not following either one:
The two methods are:
re.sub(pattern, repl, string[, count]) (docs here)
Used like so:
>>> y = re.sub(r, 'blue', x)
>>> y
'The sky is blue'
And for when you compile it before hand, as you tried, you can use:
RegexObject.sub(repl, string[, count=0]) (docs here)
Used like so:
>>> z = r.sub('blue', x)
>>> z
'The sky is blue'
answered Apr 24, 2009 at 17:46
Paolo Bergantino
490k83 gold badges523 silver badges437 bronze badges
Comments
You read the API wrong
http://docs.python.org/library/re.html#re.sub
pattern.sub(repl, string[, count])¶
r.sub(x, "blue")
# should be
r.sub("blue", x)
Comments
You have the arguments to your call to sub the wrong way round it should be:
import re
x = "The sky is red"
r = re.compile ("red")
y = r.sub("blue", x)
print x # Prints "The sky is red"
print y # Prints "The sky is blue"
Comments
By the way, for such a simple example, the re module is overkill:
x= "The sky is red"
y= x.replace("red", "blue")
print y
1 Comment
Paolo Bergantino
I had this in my original answer but the OP said he actually needed some more complex and this was just an example. +1 anyways though.
Try:
x = r.sub("blue", x)
