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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 file_sha1(path):
 """ Compute SHA1 hash of a file. """

  sha1 = hashlib.sha1()
  with open(path, "rb") as f:
    while True:
      block = f.read(2 ** 10)
      if not block:
        break
      sha1.update(block)
    return sha1.hexdigest()