I tested by https://regexr.com/
There two sample words.
BOND_aa_SB1_66-1.pdf
BOND_bb_SB2.pdf
I want to extract SB1, SB2 from each sample.
but my regular expression is not perfect.
It is working
(?<=BOND_.*_).*
But It is difficult to write the following.
I try
(?<=BOND_.*_).*(?=(_|\.))
But first sample result is 'SB1_66-1'
I just want to extract SB1
sb1 The following may or may not exist. if there is content, it can be separated by starting with _.
How should I fix it?
To extract the third underscore-separated term, we can use re.search as follows:
inp = ["BOND_aa_SB1_66-1.pdf", "BOND_bb_SB2.pdf"]
output = [re.search(r'^BOND_[^_]+_([^_.]+)', x).group(1) for x in inp]
print(output) # ['SB1', 'SB2']
s = "BOND_aa_SB1_66-1.pdf BOND_bb_SB2.pdf"
(re.findall(r'(SB\d+)', s))
['SB1', 'SB2']
Related
I have a list of records that are character vectors. Here's an example:
'1mil_0,1_1_1_lb200_ks_drivers_sorted.csv'
'1mil_0_1_lb100_ks_drivers_sorted.csv'
'1mil_1_1_lb2_100_100_ks_drivers_sorted.csv'
'1mil_1_1_lb100_ks_drivers_sorted.csv'
From these names I would like to extract whatever's between the two substrings 1mil_ and _ks_drivers_sorted.csv.
So in this case the output would be:
0,1_1_1_lb200
0_1_lb100
1_1_lb2_100_100
1_1_lb100
I'm using MATLAB so I thought to use regexp to do this, but I can't understand what kind of regular expression would be correct.
Or are there some other ways to do this without using regexp?
Let the data be:
x = {'1mil_0,1_1_1_lb200_ks_drivers_sorted.csv'
'1mil_0_1_lb100_ks_drivers_sorted.csv'
'1mil_1_1_lb2_100_100_ks_drivers_sorted.csv'
'1mil_1_1_lb100_ks_drivers_sorted.csv'};
You can use lookbehind and lookahead to find the two limiting substrings, and match everything in between:
result = cellfun(#(c) regexp(c, '(?<=1mil_).*(?=_ks_drivers_sorted\.csv)', 'match'), x);
Or, since the regular expression only produces one match, the following simpler alternative can be used (thanks #excaza for noticing):
result = regexp(x, '(?<=1mil_).*(?=_ks_drivers_sorted\.csv)', 'match', 'once');
In your example, either of the above gives
result =
4×1 cell array
'0,1_1_1_lb200'
'0_1_lb100'
'1_1_lb2_100_100'
'1_1_lb100'
For me the easy way to do this is just use espace or nothing to replace what you don't need in your string, and the rest is what you need.
If is a list, you can use a loop to do this.
Exemple to replace "1mil_" with "" and "_ks_drivers_sorted.csv" with ""
newChr = strrep(chr,'1mil_','')
newChr = strrep(chr,'_ks_drivers_sorted.csv','')
I am new to Pig. In the script that I am writing I want to perform an operation similar to this:
foreach X GENERATE REPLACE(word,'.*abc.*','abc') OR REPLACE(word,'.*def.*','def').
If the first pattern matches then abc is replaced else if second pattern is matched then def is replaced. But I suppose the syntax is incorrect. Can someone help me with the syntax?
There are a few ways to do this, but since if the regex doesn't match the string, you'll just get your string back, this is pretty compact:
Y = FOREACH X GENERATE REPLACE(REPLACE(word, '.*abc.*', 'abc'), '.*def.*', 'def');
I have a string of 5 characters out of which the first two characters should be in some list and next three should be in some other list.
How could i validate them with regular expressions?
Example:
List for First two characters {VBNET, CSNET, HTML)}
List for next three characters {BEGINNER, EXPERT, MEDIUM}
My Strings are going to be: VBBEG, CSBEG, etc.
My regular expression should find that the input string first two characters could be either VB, CS, HT and the rest should also be like that.
Would the following expression work for you in a more general case (so that you don't have hardcoded values): (^..)(.*$)
- returns the first two letters in the first group, and the remaining letters in the second group.
something like this:
^(VB|CS|HT)(BEG|EXP|MED)$
This recipe works for me:
^(VB|CS|HT)(BEG|EXP|MED)$
I guess (VB|CS|HT)(BEG|EXP|MED) should do it.
If your strings are as well-defined as this, you don't even need regex - simple string slicing would work.
For example, in Python we might say:
mystring = "HTEXP"
prefix = mystring[0:2]
suffix = mystring[2:5]
if (prefix in ['HT','CS','VB']) AND (suffix in ['BEG','MED','EXP']):
pass # valid!
else:
pass # not valid. :(
Don't use regex where elementary string operations will do.
I want to use a regular expression that would do the following thing ( i extracted the part where i'm in trouble in order to simplify ):
any character for 1 to 5 first characters, then an "underscore", then some digits, then an "underscore", then some digits or dot.
With a restriction on "underscore" it should give something like that:
^([^_]{1,5})_([\\d]{2,3})_([\\d\\.]*)$
But i want to allow the "_" in the 1-5 first characters in case it still match the end of the regular expression, for example if i had somethink like:
to_to_123_12.56
I think this is linked to an eager problem in the regex engine, nevertheless, i tried to do some lazy stuff like explained here but without sucess.
Any idea ?
I used the following regex and it appeared to work fine for your task. I've simply replaced your initial [^_] with ..
^.{1,5}_\d{2,3}_[\d\.]*$
It's probably best to replace your final * with + too, unless you allow nothing after the final '_'. And note your final part allows multiple '.' (I don't know if that's what you want or not).
For the record, here's a quick Python script I used to verify the regex:
import re
strs = [ "a_12_1",
"abc_12_134",
"abcd_123_1.",
"abcde_12_1",
"a_123_123.456.7890.",
"a_12_1",
"ab_de_12_1",
]
myre = r"^.{1,5}_\d{2,3}_[\d\.]+$"
for str in strs:
m = re.match(myre, str)
if m:
print "Yes:",
if m.group(0) == str:
print "ALL",
else:
print "No:",
print str
Output is:
Yes: ALL a_12_1
Yes: ALL abc_12_134
Yes: ALL abcd_134_1.
Yes: ALL abcde_12_1
Yes: ALL a_123_123.456.7890.
Yes: ALL a_12_1
Yes: ALL ab_de_12_1
^(.{1,5})_(\d{2,3})_([\d.]*)$
works for your example. The result doesn't change whether you use a lazy quantifier or not.
While answering the comment ( writing the lazy expression ), i saw that i did a mistake... if i simply use the folowing classical regex, it works:
^(.{1,5})_([\\d]{2,3})_([\\d\\.]*)$
Thank you.
Can anyone help me with a regex to turn:
filename_author
to
author_filename
I am using MS Word 2003 and am trying to do this with Word's Find-and-Replace. I've tried the use wildcards feature but haven't had any luck.
Am I only going to be able to do it programmatically?
Here is the regex:
([^_]*)_(.*)
And here is a C# example:
using System;
using System.Text.RegularExpressions;
class Program
{
static void Main()
{
String test = "filename_author";
String result = Regex.Replace(test, #"([^_]*)_(.*)", "$2_$1");
}
}
Here is a Python example:
from re import sub
test = "filename_author";
result = sub('([^_]*)_(.*)', r'\2_\1', test)
Edit: In order to do this in Microsoft Word using wildcards use this as a search string:
(<*>)_(<*>)
and replace with this:
\2_\1
Also, please see Add power to Word searches with regular expressions for an explanation of the syntax I have used above:
The asterisk (*) returns all the text in the word.
The less than and greater than symbols (< >) mark the start and end
of each word, respectively. They
ensure that the search returns a
single word.
The parentheses and the space between them divide the words into
distinct groups: (first word) (second
word). The parentheses also indicate
the order in which you want search to
evaluate each expression.
Here you go:
s/^([a-zA-Z]+)_([a-zA-Z]+)$/\2_\1/
Depending on the context, that might be a little greedy.
Search pattern:
([^_]+)_(.+)
Replacement pattern:
$2_$1
In .NET you could use ([^_]+)_([^_]+) as the regex and then $2_$1 as the substitution pattern, for this very specific type of case. If you need more than 2 parts it gets a lot more complicated.
Since you're in MS Word, you might try a non-programming approach. Highlight all of the text, select Table -> Convert -> Text to Table. Set the number of columns at 2. Choose Separate Text At, select the Other radio, and enter an _. That will give you a table. Switch the two columns. Then convert the table back to text using the _ again.
Or you could copy the whole thing to Excel, construct a formula to split and rejoin the text and then copy and paste that back to Word. Either would work.
In C# you could also do something like this.
string[] parts = "filename_author".Split('_');
return parts[1] + "_" + parts[0];
You asked about regex of course, but this might be a good alternative.