Deleting String Up to the First Occurrence of Certain Character

let str = `28 Mar 2017 ... helloo ... i need to remove everything until first occurrence of special charaters ...`


console.log(str.replace(/^.+?(\.\.\.) /, ''))

Remove first occurrence of comma in a string

This will do it:

if (str.match(/,.*,/)) { // Check if there are 2 commas
    str = str.replace(',', ''); // Remove the first one
}

When you use the replace method with a string rather than an RE, it just replaces the first match.

How to remove the contents of a string after the first occurrence of a character in java?

I think replaceFirst("[-+.^:,_]\d.*", "") should do what you want.

You can read that as "a 'symbol' followed by a digit followed by everything else in the string."

remove the word in a string before first occurrence of hyphen or underscore in R

Here is a solution using the dplyr and stringr packages.

string_2 regular expression removes up until the first _ or - and is replaced with MYD.

string_3 regular expression removes through the first _ or -.

library(dplyr)
library(stringr)

df <- tibble(string_1 = c("Sec_GHTY_WE", "NewSec_JOL_ru", "Sec-KIH-YRK", "Sec_PWq-FTF", "NewSec-LPO-WE"))


df %>% 
  mutate(
    string_2 = str_replace(string_1, pattern = "^.*?(?=-|_)", "MYD"),
    string_3 = str_remove(string_1, pattern = "^.*?(_|-)")
    )

#> # A tibble: 5 x 3
#>   string_1      string_2    string_3
#>   <chr>         <chr>       <chr>   
#> 1 Sec_GHTY_WE   MYD_GHTY_WE GHTY_WE 
#> 2 NewSec_JOL_ru MYD_JOL_ru  JOL_ru  
#> 3 Sec-KIH-YRK   MYD-KIH-YRK KIH-YRK 
#> 4 Sec_PWq-FTF   MYD_PWq-FTF PWq-FTF 
#> 5 NewSec-LPO-WE MYD-LPO-WE  LPO-WE

^{Created on 2020-11-16 by the reprex package (v0.3.0)}

How to remove anything that starts with specific character (@) in various locations in string in R?

We may change the pattern to match zero or more space (\\s*) followed by @ and one or more non-white space (\\S+) in str_remove_all to remove those substring

library(stringr)
library(dplyr)
Customer %>%
     mutate(Cleaned_Tweet = str_remove_all(Tweet, "\\s*@\\S+"))

-output

 ID                                                                 Tweet                                         Cleaned_Tweet
1  1                    @ChipotleTweets @ChipotleTweets Becky is very nice                                    Becky is very nice
2  2 Happy Halloween! I now look forward to $3 booritos at @ChipotleTweets Happy Halloween! I now look forward to $3 booritos at
3  3           Considering walking to @.ChipotleTweets in my llama onesie.            Considering walking to in my llama onesie.

NOTE: str_remove just removes the first instance of match i.e. if there are more than one match in a single string, it skips the others and matches only the first. We need str_remove_all for removing all instances of matching patterns.

data

Customer <- structure(list(ID = 1:3, Tweet = c("@ChipotleTweets @ChipotleTweets Becky is very nice", 
"Happy Halloween! I now look forward to $3 booritos at @ChipotleTweets", 
"Considering walking to @.ChipotleTweets in my llama onesie."
)), class = "data.frame", row.names = c(NA, -3L))

Replace the first occurrence of a character within a string in R

The g in gsub stands for global, indicating that it will match all occurrences. If you use sub instead of gsub, only the first occurrence will be matched and replaced. See ?gsub for details, in the Description:

sub and gsub perform replacement of the first and all matches respectively.

And, if you only want to replace the colon, your pattern should just be ":", ".*:" will match and replace everything up through the last colon. If you want to replace everything up through the first colon, using sub and ? to make * not greedy will work.

x = "Request(123): \n Element1: 123123 \n Element2: 456456"

## match everything up through last colon
sub(".*:", "", x)
# [1] " 456456"

## not greedy, match everything up through first colon
sub(".*?:", "", x)
# [1] " \n Element1: 123123 \n Element2: 456456"

## match first colon only
## since we don't need regex here, fixed = TRUE will speed things up
sub(":", "", x, fixed = TRUE)
#[1] "Request(123) \n Element1: 123123 \n Element2: 456456"

## compare to gsub, match every colon
gsub(":", "", x, fixed = TRUE)
# [1] "Request(123) \n Element1 123123 \n Element2 456456"

Removing the first occurrence of a string from another string in Python

Refactoring your code

def remove(substring, string):
    sublen = len(substring)
    new_string = "" 

    for i in range(len(string)):
    
      if string[i:i+sublen] == substring:
          # found so append remaining string
          new_string += string[i+sublen:]
          break
      else:
          new_string += string[i]  # not found so append character

    return new_string 

print(remove("today", 'today is friday, the last friday of the month')) 

Output

is friday, the last friday of the month

Alternate Solution (from your link)

def remove(substring, string)
    return string.replace(substring, '', 1)

This uses the replace function to replace the first occurrence of a string.

Python String | replace provides a good description of how this works.

Removing beginning of a string until the first instance of a specific character

If you can rely on - preceding the name and you're not adamant on using a regex:

s = '| | +-out\windows-x86-MD-mbcs-vs2008-rel\bin\VisualStudio08-32bit.exe'
print s.split('-', 1)[1]

Output: out\windows-x86-MD-mbcs-vs2008-relin\VisualStudio08-32bit.exe

How to remove all characters before a specific character in Java?

You can use .substring():

String s = "the text=text";
String s1 = s.substring(s.indexOf("=") + 1);
s1.trim();

then s1 contains everything after = in the original string.

s1.trim()

.trim() removes spaces before the first character (which isn't a whitespace, such as letters, numbers etc.) of a string (leading spaces) and also removes spaces after the last character (trailing spaces).

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