The Regex Quantifier Betrayal

Description

A very tight dark-theme code screenshot shows syntax-highlighted Python-like regex code, including a visible fragment resembling `re.findall('index":"(\d*)_(\d*)"', ...)` and a following line converting captured groups with `int(lGroup[0][0])` and another `int(...)` call. The key visible pattern uses `\d*`, which means zero or more digits, rather than `\d+`, which would require at least one digit. The sibling caption says, "The Look your regex gives you when you use asterisks instead of plus," framing the crop as a classic regular-expression footgun. The technical humor is that one quantifier character can silently admit empty captures and push the failure downstream into parsing or type conversion.

Common Tags

RegularExpressions SubtleBugs PatternMatching CodingMistakes BugsInSoftware EdgeCase Debugging BugFixing EdgeCaseHandling CodingHumor Python DeveloperHumor InputValidation StringHandlingLibraries CodeReadability

Comments

Anonymous ★ Top Pick The gap between `\d*` and `\d+` is exactly one character wide and somehow still large enough to fit an outage.

Anonymous ★ Top Pick

The gap between `\d*` and `\d+` is exactly one character wide and somehow still large enough to fit an outage.
Deleted Account 5y

parsing json with regex why
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5. @gas2600 5y
  
  coz can и лан
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7. @akionka 5y
  
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10. @nenten 5y
  
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Deleted Account 5y

validating is not parsing
Deleted Account 5y

regex in the pic won't match "index":\n"245_445" which is a totally valid json
1. @ogroleg 5y
  
  👍
@willowfragment 5y

"asterisks"... "plus"... why not call them what they are, which is "zero or more occurrences " and "one or more occurrences "
@s2504s 5y

B/c this is easy?

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The Regex Quantifier Betrayal

Description

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Common Tags

Comments

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