I am trying to work out how to do something using regular expressions.
Basically, I want to check if a number is equal to a base number (i.e. 2) to the power of n.
For example, I need something thats checks if number i == 2, 4, 8, 16 or 32 then do something.
Edit:
The problem lies where the number is actually coming from a varchar column in a legacy database. I could parse it out then do something like kobi reccommended but there is another problem where the number is in a delimited list i.e. (1,2,3,32). Therefore, I thought it would be easier to use regex as it would save a number of steps.
Thanks in advance.
In Python:
import re
a = str(bin(number))
if re.match(r"[^1]*1[^1]*$", a):
print "power of two"
Related
I have multiple cells that I am attempting to extract a number from, and need help finding a regex alternative.
The cells range in the following formats:
asdfs. Seat#29 asfddsa
asdfsa. Seat#5d
asdfasN/A . Seat#22 as789fsd
Seat#111 words33
The closest that I came to a solution is:
=IFERROR(TRIM(MID([#DisplayName],FIND("#",[#DisplayName])+1,3)),"")
As you can see this will extract most of the numbers but for some it leaves a character at the end.
The only commonality is the # preceding the seat number. I am trying to extract only the seat number, no other numbers.
I cannot use VBA, this must be done using formulas. I have figured this out once before but stupidly pasted over the formulas with a values only paste.
This can be done utilizing a flash fill, but I was hoping for a more stable formula.
If you want just the numbers then use:
=--MID(A1,FIND("#",A1)+1,AGGREGATE(15,6,ROW(1:5)/(ISERROR(--MID(REPLACE(A1,1,FIND("#",A1),""),ROW(1:5),1))),1)-1)
If you want the letter also then:
=MID(A1,FIND("#",A1)+1,FIND(" ",REPLACE(A1,1,FIND("#",A1),""))-1)
If you do not need the letter following the seat number, you can use
.*#(\d+)
Edit for clarity: Excel does not have regex functions built in. You will either have to use a UDF (I can help with that if you'd like) or use a non-regex solution.
Here is a solution without VBA to extract all numbers inside the strings.
https://drive.google.com/open?id=1Fk6VFznD3i8s6scADy_vXCEj-1zQpBPW
Sheet #3
I'm using Selenium IDE and can't figure out how to select a given element that has a certain attribute which contains some text (number) of a certain length after a specified character.
In order to better understand what exactly I would like to achieve please see below an example.
I have the following HTML element:
<div><h2 class="attribute" onclick="PropertyPopup.Show(63854, 4065)">test test</h2></div>
In my case both the numbers in the bracket (63854 and 4065) are changing dynamically and I'm mostly interested in the second number (4065). This can have a length of 4 or 7 so I would need an XPATH (combined with regexp?) that would extract only those elements where this number has a length of 4 for example (like in the above example).
So far I've used the following XPATH:
//div[h2[#onclick][string-length(#onclick)<=31]]
This is working fine at the moment (since in most cases when the second number has a length of 4, the whole line will have less (or equal) than 31 characters) but if the first number will contain 6 numbers (and the whole line will have 32 characters), the above example will not be selected. If I would put "<=32", then in some cases, it would select those elements where the second number has a length of 7 (like when the first number has a length of 3 and the second 7).
I've tried to use something like the below:
//div[h2[#onclick][contains(#onclick,', \d{4}']]
but this will not be recognized as a regexp and will look for an 'onclick' attribute that contain the word ", \d{4}".
Is there anything I could do in order to select the node only based on the second number (its length)?
thank you,
Szabi
You could try something like this:
//div[string-length(normalize-space(substring-before(substring-after(h2/#onclick,','),')')))=4]
I'm currently using ([1-9]|1[0-2]) to represent inputs from 1 to 12. (Leading zeros not allowed.)
However it seems rather hacky, and on some days it looks outright dirty.
☞ Is there a proper in-built way to do it?
☞ What are some other ways to represent number ranges?
I tend to go with forms like [2-9]|1[0-2]? which avoids backtracking, though it makes little difference here. I've been conditioned by XML Schema to avoid such "ambiguities", even though regex can handle them fine.
Yes, the correct one:
[1-9]|1[0-2]
Otherwise you don't get the 10.
Here is the better answer, with exact match from 1 - 12.
(^0?[1-9]$)|(^1[0-2]$)
Previous answers doesn't really work well with HTML input regex validation, where some values like '1111' or '1212' will still treat it as a valid input.
You can use:
[1-9]|1[012]
How about:
^[1-9]|10|11|12$
Matches 0-9 or 10 or 11 or 12. thats it, nothing else is matched.
You can try this:
^[1-9]$|^[1][0-2]$
Use the following pattern (0?[1-9]|1[0-2]) use this which will return values from 1 to 12 (January to December) even if it initially starts with 0 (01, 02, 03, ..., 09, 10, 11, 12)
The correct patter to validate numbers from 1 to 12 is the following:
(^[1-9][0-2]$)|(^[1-9]$)
The above expression is useful when you have an input with type number and you need to validate month, for example. This is because the input type number ignores the 0 in front of any number, eg: 01 it returns 1.
You can see it in action here: https://regexr.com/5hk0s
if you need to validate string numbers, I mean, when you use an input with type text but you expect numbers, eg: expiration card month, or months the below expression can be useful for you:
((^0[1-9]$)|(^1[0-2]$))
You can see it in action here https://regexr.com/5hkae
I hope this helps a lot because it is very tricky.
Regards.
In python this matches any number between 1 - 12:
12|11|10|9|8|7|6|5|4|3|2|1
The descending order matters. In ascending order 10, 11 and 12 would match 1 instead as regex usually pick the first matching value.
I have a list of numbers that I want to find at least 3 of...
here is an example
I have a large list of numbers in a sql database in the format of (for example)
01-02-03-04-05-06
06-08-19-24-25-36
etc etc
basically 6 random numbers between 0 and 99.
Now I want to find the strings where at least 3 of a set of given numbers occurs.
For example:
given: 01-02-03-10-11-12
return the strings that have at least 3 of those numbers in them.
eg
01-05-06-09-10-12 would match
03-08-10-12-18-22 would match
03-09-12-18-22-38 would not
I am thinking that there might be some algorithm or even regular expression that could match this... but my lack of computer science textbook experience is tripping me up I think.
No - this is not a homework question! This is for an actual application!
I am developing in ruby, but any language answer would be appreciated
You can use a string replacement to replace - with | to turn 01-02-03-10-11-12 into 01|02|03|10|11|12. Then wrap it like this:
((01|02|03|10|11|12).*){3}
This will find any of the digit pairs, then ignore any number of characters... 3 times. If it matches, then success.
I would like to write a regular expression to validate and input field against the following arguments:
field is required (cannot be
empty)
field must not be a negative number
field must be a validate decimal
number to two decimals (eg. 1 or 1.3
or 1.23)
field can be any valid number between 0 and 100 or an 'e'
Regular expressions find great use in checking format, but you're wishing to use it to do a subset of floating point number parsing and bounds checking. Be kind to yourself and the person who will maintain your code after you're gone: check if it's an 'e', else read it into a float and check the bounds.
You can use: ^(100|\d{1,2}(\.\d{1,2})?|e)$
However, it would be simpler and more readable to use your language's float parsing/casting functions.
EDIT: Some variations based on the comments:
Allowing 100.0 and 100.00: ^(100(\.0{1,2})?|\d{1,2}(\.\d{1,2})?|e)$
Disallowing leading zeroes: ^(100(\.0{1,2})?|[1-9]?\d(\.\d{1,2})?|e)$
^(?:100|\d{1,2}(?:\.\d{1,2})?|e)$
Hmm does this work for you?
^((100|[0-9]{1,2})(\.[0-9]{1,2})?)|(e)$
Whay environment is this for? Any particular regex standard it must adhere to?
Constraints on numeric values (such as "> 100", or "<= 5.3") can make regexes rather complicated. These types of contraints are better checkedin application logic. Then you can have a simpler (and easier to understand) pattern:
^(([0-9]{1,3})(\.[0-9]{1,2})?)|(e)$
And then extract the capture group for the first 3 digits and validate that separately.
Edit:
Ok I think this one should do it (last one because my eyes are getting tired):
^(100(\.0{1,2})?)|([0-9]{1,2})(\.[0-9]{1,2})?|(e)$
Will also allow 100.00 or 100.0