On Sunday, July 6, 2014 8:09:57 AM UTC-4, Devin Jeanpierre wrote: > On Sun, Jul 6, 2014 at 4:51 AM, <rxjw...@gmail.com> wrote: > > > Hi, > > > > > > I just begin to learn Python. I do not see the usefulness of '*' in its > > > description below: > > > > > > > > > > > > > > > The first metacharacter for repeating things that we'll look at is *. * > > doesn't > > > match the literal character *; instead, it specifies that the previous > > character > > > can be matched zero or more times, instead of exactly once. > > > > > > For example, ca*t will match ct (0 a characters), cat (1 a), caaat (3 a > > > characters), and so forth. > > > > > > > > > > > > It has to be used with other search constraints? > > > > (BTW, this is a regexp question, not really a Python question per se.) > > > > That's usually when it's useful, yeah. For example, [0-9] matches any > > of the characters 0 through 9. So to match a natural number written in > > decimal form, we might use the regexp [0-9][0-9]*, which matches the > > strings "1", "12", and "007", but not "" or "Jeffrey". > > > > Another useful one is `.*` -- `.` matches exactly one character, no > > matter what that character is. So, `.*` matches any string at all. > > > > The power of regexps stems from the ability to mix and match all of > > the regexp pieces in pretty much any way you want. > > > > -- Devin
Would you give me an example using your pattern: `.*` -- `.`? I try it, but it cannot pass. (of course, I use it incorrectly) -- https://mail.python.org/mailman/listinfo/python-list
