The fourth bird questions

The fourth bird answers

• Splitting a comma- and semicolon-delimited string in R
• Python 2.7 : matching expression using regex
• Invalid regular expression: look-behind requires fixed-width pattern
• Python regex.findall not finding all matches of shorter length
• C# Regex Match parenthesis group except if it contains specified word
• Regular expression that finds [abc] but not [;;abc]
• Bookmark consecutive lines that start with a number
• Bash: Extract multiple entries from each line
• regular expression to only allow numbers, numbers with dot, & and space
• Unable to get customized result using regex