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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def git_pretty():
 """returns a pretty summary of the commit or unkown if not in git repo"""

    if git_repo() is None:
        return "unknown"
    pretty = subprocess.check_output(
        ["git", "log", "--pretty=format:%h %s", "-n", "1"])
    pretty = pretty.decode("utf-8")
    pretty = pretty.strip()
    return pretty