Cron Expression in PY
Validate standard 5-field Unix cron expressions: minute, hour, day-of-month, month, day-of-week.
Try it in the PY tester →Pattern
regexPY
^(\*|([0-5]?\d))\s+(\*|([01]?\d|2[0-3]))\s+(\*|([1-9]|[12]\d|3[01]))\s+(\*|([1-9]|1[0-2]))\s+(\*|[0-7])$Python (re) code
pyPython
import re
pattern = re.compile(r"^(\*|([0-5]?\d))\s+(\*|([01]?\d|2[0-3]))\s+(\*|([1-9]|[12]\d|3[01]))\s+(\*|([1-9]|1[0-2]))\s+(\*|[0-7])$")
input_text = "0 9 * * 1"
for m in pattern.finditer(input_text):
print(m.group(0))Stdlib `re` module — no third-party dependency. Works on Python 3.6+.
How the pattern works
Each of the five fields is validated against its allowed range. Minute: 0–59. Hour: 0–23. Day-of-month: 1–31. Month: 1–12. Day-of-week: 0–7 (0 and 7 both mean Sunday). Each field also accepts * for any value.
Examples
Input
0 9 * * 1Matches
0 9 * * 1
Input
*/15 * * * *No match
—Input
60 25 * * *No match
—