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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 sha_hash_file(filename):
 """ Compute the SHA1 hash of filename """

    hash_sha = hashlib.sha1()

    with open(filename, 'rb') as f:
        for chunk in iter(lambda: f.read(1024*1024), b""):
            hash_sha.update(chunk)

    return hash_sha.hexdigest()