I know there is plenty of info about regex available but I can’t figure it out somehow. I have an array1 = ['\n 1.979   \n, \n 1.799   \n'] which looks like this but the numbers vary but are always in this format so the regex = re.compile(r'\d.\d\d\d') which matches perfectly in notepad++ but doesn’t seems to work in python. import re  regex = re.compile(r'\d.\d\d\d') filteredarray= [i for i in array1 if regex.match(i)]  print(filteredarray)  what am I missing? Thanks in Advance
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What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.
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I notice a lot of bash utilities like ls, cp, mv, grep use regular expressions and pattern matching. For instance symbols like * [] {} etc.   However, I find this to be different in some regard to other regular expression tutorials I find on the Internet. Is there a specific standard that these utilities follow or a comprehensive list of shortcuts somewhere?   Thank you
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I have a Python regular expression that contains a group which can occur zero or many times - but when I retrieve the list of groups afterwards, only the last one is present. Example:  re.search("(\w)*", "abcdefg").groups()  this returns the list ('g',)  I need it to return ('a','b','c','d','e','f','g',)  Is that possible? How can I do it?
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Consider the following piece of Markdown code:  This is some regular text.      &gt;&gt;&gt; def factorial(n):     ...     return 1 if n &lt; 2 else n * factorial(n - 1)     ...   * This is a list item.      &gt;&gt;&gt; def factorial(n):     ...     return 1 if n &lt; 2 else n * factorial(n - 1)     ...    Notice that the second code block is preceded by a list item.   Why is the factorial code not properly formatted under these circumstances? To demonstrate the problem, I'll insert the Markdown code show above:    This is some regular text.  &gt;&gt;&gt; def factorial(n): ...     return 1 if n &lt; 2 else n * factorial(n - 1) ...     This is a list item                 def factorial(n):       ...     return 1 if n &lt; 2 else n * factorial(n - 1)       ...               This applies to numbered as well as unnumbered lists.
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I need to delete some Unicode symbols from the string 'بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ'  I know they exist here for sure. I tried:  re.sub('([\u064B-\u0652\u06D4\u0670\u0674\u06D5-\u06ED]+)', '', 'بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ')   but it doesn't work. String stays the same. What am I doing wrong?
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Regex.IsMatch( "foo", "[\U00010000-\U0010FFFF]" )    Throws: System.ArgumentException: parsing "[-]" - [x-y] range in reverse order.  Looking at the hex values for \U00010000 and \U0010FFF I get: 0xd800 0xdc00 for the  first character and 0xdbff 0xdfff for the second.  So I guess I have really have one problem. Why are the Unicode characters formed with \U split into two chars in the string?
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This will surely be an easy one but it is really bugging me.   I have a script that reads in a webpage and uses  to parse it. From the soup I extract all the links as my final goal is to print out the link.contents.  All of the text that I am parsing is ASCII. I know that Python treats strings as unicode, and I am sure this is very handy, just of no use in my wee script.   Every time I go to print out a variable that holds 'String' I get [u'String'] printed to the screen. Is there a simple way of getting this back into just ascii or should I write a regex to strip it?
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I didn't get the answer to this anywhere. What is the runtime complexity of a Regex match and substitution?  Edit: I work in python. But would like to know in general about most popular languages/tools (java, perl, sed).
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Can anyone help me with this question: I know it before, but I have tried to solve it myself and didnt succeed. what is the regular expression for this language: L=all words that have 00 or 11 but not both.  Thank you!
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A friend asked me this and I was stumped: Is there a way to craft a regular expression that matches a sequence of the same character? E.g.,  match on 'aaa', 'bbb', but not 'abc'?  m|\w{2,3}|    Wouldn't do the trick as it would match 'abc'.  m|a{2,3}|    Wouldn't do the trick as it wouldn't match 'bbb', 'ccc', etc.
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What is an easy way in Python to format integers into strings representing thousands with K, and millions with M, and leaving just couple digits after comma?  I'd like to show 7436313 as 7.44M, and 2345 as 2,34K.  Is there some % string formatting operator available for that? Or that could be done only by actually dividing by 1000 in a loop and constructing result string step by step?
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Is there a way to specify a regular expression to match every 2nd occurrence of a pattern in a string?  Examples   searching for a against string abcdabcd should find one occurrence at position 5 searching for ab  against string abcdabcd should find one occurrence at position 5 searching for dab  against string abcdabcd should find no occurrences searching for a against string aaaa should find two occurrences at positions 2 and 4
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What is the most efficient way of testing an input string whether it contains a numeric value (or conversely Not A Number)? I guess I can use Double.Parse or a regex (see below) but I was wondering if there is some built in way to do this, such as javascript's NaN() or IsNumeric() (was that VB, I can't remember?).  public static bool IsNumeric(this string value) {     return Regex.IsMatch(value, "^\\d+$"); }
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Unfortunately, despite having tried to learn regex at least one time a year for as many years as I can remember, I always forget as I use them so infrequently. This year my new year's resolution is to not try and learn regex again - So this year to save me from tears I'll give it to Stack Overflow. (Last Christmas remix).  I want to pass in a string in this format {getThis}, and be returned the string getThis. Could anyone be of assistance in helping to stick to my new year's resolution?    Related questions on Stack Overflow:
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I'm looking for a  way to convert numbers to string format, dropping any redundant '.0'   The input data is a mix of floats and strings. Desired output:  0   --> '0'  0.0 --> '0'  0.1 --> '0.1'  1.0 --> '1'  I've come up with the following generator expression, but I wonder if there's a faster way:  (str(i).rstrip('.0') if i else '0' for i in lst)   The truth check is there to prevent 0 from becoming an empty string.  EDIT: The more or less acceptable solution I have for now is this:  ('%d'%i if i == int(i) else '%s'%i for i in lst)   It just seems strange that there is no elegant way to handle this (fairly straightforward) case in python.
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Is there a regular expression that matches valid regular expressions?   (I know there are several flavors of regexps. One would do.)
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I allow users to enter a regular expression to match IP addresses, for doing an IP filtration in a related system. I would like to validate if the entered regular expressions are valid as a lot of userse will mess op, with good intentions though.  I can of course do a Regex.IsMatch() inside a try/catch and see if it blows up that way, but are there any smarter ways of doing it? Speed is not an issue as such, I just prefer to avoid throwing exceptions for no reason.