Why does the expression "fire"?

Question

Python

Program in Python.

line='/link/abcd'
pattern='/link/abcd(\/.*)?'
m=re.match(pattern,line)

Tell me why match works with line = '/link/abcdefffsd' for example?
It was assumed that it should work only on a link like
/link/abcd
/link/abcd/blablabla
i.e. either the link itself, or the link ends with / and then any characters after the slash.

Answer 1

You have an extra backslash in "\" and the string is not raw. In short, it is correct to write like this:
The tail slash is not required, but if it is, any characters in any number, including zero, are allowed after it.

Answer 2

And if you put "$" at the end of the pattern? (without quotes)

Answer 3

import re

line='/link/abcd/fdfs'
pattern='/link/abcd(\/.*)$'
m=re.match(pattern,line)
if (m):
  print "Okay"
else:
  print "WTF????"

So do it

Answer 4

import re

line='/link/abcd'
pattern='^/link/(abcd)/(.*)$'
m=re.match(pattern,line)
if (m):
  print "Okay"
else:
  print "WTF????"

Answer 5

Works because of what? at the end (i.e. the part in brackets is optional). What you want is done with the regex
/link/abcd(/.*)?$

Answer 6

pattern='/link/abcd(\/.*)?$'

Answer 7

The .* expression matches, among other things, the empty string. What you want to achieve, as I understand it, is (\/.+)? See also tynts .