Add division symbol to regular expression
^(\+|-)?(\d+)?([.]?\d*)?$
Look to add slash symbol like expression accepts 4/5.
Add an optional expression containing / and the regexp that matches a number.
^(\+|-)?(\d*)([.]?\d*)?(?:/(\+|-)?(\d*)([.]?\d*)?)?$
BTW, (\d+)? can be simplified to (\d*).
You should use a regex that is more in line with how a language parser would
parse a integer or non-exponential decimal.
That said, like Barmar said, you can just append an optional slash plus number.
^(?:([+-]?)(\d+(?:\.\d*)?|\.\d+)(?:\s*/\s*([+-]?)(\d+(?:\.\d*)?|\.\d+))?)$
Formatted
^
(?:
( [+-]? ) # (1), plus/minus sign
( # (2 start), number
\d+
(?: \. \d* )?
| \. \d+
) # (2 end)
(?: # Optional division
\s*
/ # division sign
\s*
( [+-]? ) # (3), plus/minus sign
( # (4 start), number
\d+
(?: \. \d* )?
| \. \d+
) # (4 end)
)?
)
$
Related
I'm struggling with that one. I want to capture the content of parenthesis where there isn't only digit %. This means I would want to capture this (essiccato, ricco di flavonoidi) or (ricco di 23% pollo, in parte essiccato, in parte idrolizzato) but not this (23 %)or (23)or (23 %)
Here is an exemple : https://regex101.com/r/yW4aZ3/896
So far I'm there : \([^()][^()]*\)
You may use
r'\((?!\s*\d+(?:[.,]\d+)?\s*)[^()]+\)'
See the regex demo and the regex graph:
Details
\( - a ( char
(?!\s*\d+(?:[.,]\d+)?\s*) - a negative lookahead that matches a location not immediately followed with
\s* - 0+ whitespaces
\d+ - 1+ digits
(?:[.,]\d+)? - an optional occurrence of . or , and 1+ digits
\s* - 0+ whitespaces
[^()]+ - 1+ chars other than ( and )
\) - a ) char.
You might use a negative lookahead what follows after the opening parenthesis is not digits followed by an optional percentage sign:
\((?!\s*\d+\s*%?\s*\))[^)]+\)
Explanation
\( Match (
(?! Negative lookahead, assert what is on the right is not
\s*\d+\s*%?\s*\) match 1+ digits followed by an optional % till )
) Close lookahead
[^)]+\) Match 1+ times any char except ), then match )
Regex demo
Assuming that (...) are all balanced and there is no escaping of parentheses inside, you may use this regex with a character class and 2 negated character classes:
\([\d%]*[^%\d()][^()]*\)
Updated RegEx Demo
RegEx Details
\(: Match opening (
[\d%]*: Match 0 or more of any characters that is either a digit or %
[^%\d()]: Match a character that is not (, ), % and a digit
[^()]*: Match 0 or more of any characters that are not ( and not a )
\): Match closing )
I have this pattern (?<!')(\w*)\((\d+|\w+|.*,*)\) that is meant to match strings like:
c(4)
hello(54, 41)
Following some answers on SO, I added a negative lookbehind so that if the input string is preceded by a ', the string shouldn't match at all. However, it still partially matches.
For example:
'c(4) returns (4) even though it shouldn't match anything because of the negative lookbehind.
How do I make it so if a string is preceded by ' NOTHING matches?
Since nobody came along, I'll throw this out to get you started.
This regex will match things like
aa(a , sd,,,f,)
aa( as , " ()asdf)) " ,, df, , )
asdf()
but not
'ab(s)
This will fix the basic problem (?<!['\w])\w*
Where (?<!['\w]) will not let the engine skip over a word char just
to satisfy the not quote.
Then the optional words \w* to grab all the words.
And if a 'aaa( quote is before it, then it won't match.
This regex here embellishes what I think you are trying to accomplish
in the function body part of your regex.
It might be a little overwhelming to understand at first.
(?s)(?<!['\w])(\w*)\(((?:,*(?&variable)(?:,+(?&variable))*[,\s]*)?)\)(?(DEFINE)(?<variable>(?:\s*(?:"[^"\\]*(?:\\.[^"\\]*)*"|'[^'\\]*(?:\\.[^'\\]*)*')\s*|[^()"',]+)))
Readable version (via: http://www.regexformat.com)
(?s) # Dot-all modifier
(?<! ['\w] ) # Not a quote, nor word behind
# <- This will force matching a complete function name
# if it exists, thereby blocking a preceding quote '
( \w* ) # (1), Function name (optional)
\(
( # (2 start), Function body
(?: # Parameters (optional)
,* # Comma (optional)
(?&variable) # Function call, get first variable (required)
(?: # More variables (optional)
,+ # Comma (required)
(?&variable) # Variable (required)
)*
[,\s]* # Whitespace or comma (optional)
)? # End parameters (optional)
) # (2 end)
\)
# Function definitions
(?(DEFINE)
(?<variable> # (3 start), Function for a single Variable
(?:
\s*
(?: # Double or single quoted string
"
[^"\\]*
(?: \\ . [^"\\]* )*
"
|
'
[^'\\]*
(?: \\ . [^'\\]* )*
'
)
\s*
| # or,
[^()"',]+ # Not quote, paren, comma (can be whitespace)
)
) # (3 end)
)
I am having problems creating a regular expresion. It needs to fullfill the following:
1) Has 8-12 characters
2) At least 1 uppercase letter
3) At least 3 lowercase letters
4) At least 1 number
5) At least 1 special character
6) Has to start with a lowercase, upercase or numeric
7) Maximum of 2 repeating characters
Thanks in advance!
This should work
^(?=.*[A-Z])(?=(?:.*[a-z]){3})(?=.*[0-9])(?=.*[!"#$%&'()*+,\-./:;<=>?#[\]^_`{|}~])(?=(?:(.)(?!\1\1))+$)[a-zA-Z0-9].{7,11}$
Explained / Expanded
^ # BOS
(?= .* [A-Z] ) # 1 upper
(?=
(?: .* [a-z] ){3} # 3 lower
)
(?= .* [0-9] ) # 1 number
(?=
.* [!"#$%&'()*+,\-./:;<=>?#[\]^_`{|}~] # 1 special
)
(?= # Maximum 2 repeating
(?:
( . ) # (1)
(?! \1 \1 )
)+
$
)
[a-zA-Z0-9] # First alnum
.{7,11} # 8 to 12 max chars
$ # EOS
What you got so far?
Also, which set of regex are you using ?
I'd start with the length of the expression
Restrict it to be 8-12, something like [a-zA-Z]{8,12}
For the requirements on the first one you can use a []+
For the other requirements it's a little tricker
I searched a lot but can not find this regular expression. My problem is that I made a calculator but can not validate my display entirely. My case is with the dot
I need my regular expression to be: digit dot digit operator digit dot ( 1.23+1.23+1.). The dot must be placed only once not like (1..23+ 1.1.1). I have found similar regular expression but it didn't cover the case (1.23 +1.)
Here is my regEx -> /[0-9-+/*]+(\.[0-9][0-9]?)?/g
Could use this
^[+-]?(?:\d+(?:\.\d*)?|\.\d+)(?:[+-](?:\d+(?:\.\d*)?|\.\d+))*$
Expanded:
^ # BOS
[+-]? # Optional Plus or minus
(?: # Decimal term
\d+
(?: \. \d* )?
| \. \d+
)
(?: # Optionally, many more terms
[+-] # Required Plus or minus
(?: # Decimal term
\d+
(?: \. \d* )?
| \. \d+
)
)*
$ # EOS
Check this out(demo):
/^(([-+*\/ ]+)?(\b(\d+\.\d+)\b|\d))+$/
but it will work only if there is one equation per string - it matches at beginning (^) and ant the end ($) of a string. However you can also use it with /m or/and /g modifiers.
EDIT
If it is only about '–' character it is enough to add it to character class:
/^(([-–+*\/ ]+)?(\b(\d+\.\d+)\b|\d))+$/
You can test everything out here:
I would like to extract the value of individual variables paying attention to the different ways they have been defined. For example, for dtime we want to extract 0.004. It also has to be able to interpret exponential numbers, like for example for variable vis it should extract 10e-6.
The problem is that each variable has its own number of white spaces between the variable name and the equal sign (i dont have control on how they have been coded)
Text to test:
dtime = 0.004D0
case = 0
newrun = 1
periodic = 0
iscalar = 1
ieddy = 1
mg_level = 5
nstep = 20000
vis = 10e-6
ak = 10e-6
g = 9.81D0
To extract dtime's value this REGEX works:
(?<=dtime =\s)[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?
To extract dtime's value this REGEX works:
(?<=vis =\s)[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?
The problem is that I need to know the exact number of spaces between the variable name and the equal sign. I tried using \s+ but it does not work, why?
(?<=dtime\s+=\s)[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?
If you are using PHP or PERL or more generally PCRE then you can use the \K flag to solve this problem like this:
dtime\s+=\s\K[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?
^^
Notice the \K, it tells the expression to ignore everything
behind it as if it was never matched
Regex101 Demo
Edit: I think you need to capture the number in a capturing group if you can't use look behinds or eliminate what was matched so:
dtime\s*=\s*([-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?)
(?<=dtime\s+=\s) is a variable length lookbehind because of \s+. Most(not all) engines support only a 'fixed' length lookbehind.
Also, your regex requires a digit before the exponential form, so if there is no digit, it won't match. Something like this might work -
# dtime\s*=\s*([-+]?[0-9]*\.?[0-9]*(?:[eE][-+]?[0-9]+)?)
dtime \s* = \s*
( # (1)
[-+]? [0-9]* \.? [0-9]*
(?: [eE] [-+]? [0-9]+ )?
)
Edit: After review, I see you're trying to fold multiple optional forms into one regex.
I think this is not really that straight forward. Just as interest factor, this is probably a baseline:
# dtime\s*=\s*([-+]?(?(?=[\d.]+)(\d*\.\d+|\d+\.\d*|\d+|(?!))|)(?(?=[eE][-+]?\d+)([eE][-+]?\d+)|))(?(2)|(?(3)|(?!)))
dtime \s* = \s*
( # (1 start)
[-+]? # optional -+
(?(?= # conditional check for \d*\.\d*
[\d.]+
)
( # (2 start), yes, force a match on one of these
\d* \. \d+ # \. \d+
| \d+ \. \d* # \d+ \.
| \d+ # \d+
| (?!) # or, Fail the match, the '.' dot is there without a number
) # (2 end)
| # no, match nothing
)
(?(?= # conditional check for [eE] [-+]? \d+
[eE] [-+]? \d+
)
( [eE] [-+]? \d+ ) # (3), yes, force a match on it
| # no, match nothing
)
) # (1 end)
(?(2) # Conditional check - did we match something? One of grp2 or grp3 or both
| (?(3)
| (?!) # Did not match a number, Fail the match
)
)