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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 parse_env_file(env_file):
 """ Reads a line-separated environment file. The format of each line should be "key=value". """

    environment = {}

    with open(env_file, 'r') as f:
        for line in f:

            if line[0] == '#':
                continue

            line = line.strip()
            if not line:
                continue

            parse_line = line.split('=', 1)
            if len(parse_line) == 2:
                k, v = parse_line
                environment[k] = v
            else:
                raise errors.DockerException(
                    'Invalid line in environment file {0}:\n{1}'.format(
                        env_file, line))

    return environment