Append a Log

追加日志

≈ 20 min · python-file-io · Open in WolfCode

Mode 'a' = append. Mode 'w' = erase. Pick the wrong one and your log loses history every call.

Python · runnable

def append_log(path, message):
    with open(path, "a") as f:
        f.write(message + "\n")

def read_log(path):
    with open(path) as f:
        return [line.rstrip("\n") for line in f]

# Three calls — all three messages survive.
append_log("audit.log", "user logged in")
append_log("audit.log", "user clicked submit")
append_log("audit.log", "user logged out")

for line in read_log("audit.log"):
    print(line)

Loading Python runtime (~5 MB, one-time)…

Append a Log

From ATBS ch.9