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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 a(text, mode='exec', indent=' ', file=None):
 """ Interactive convenience for displaying the AST of a code string. Writes a pretty-formatted AST-tree to `file`. Parameters text : str Text of Python code to render as AST. mode : {'exec', 'eval'}, optional Mode for `ast.parse`. Default is 'exec'. indent : str, optional String to use for indenting nested expressions. Default is two spaces. file : None or file-like object, optional File to use to print output. If the default of `None` is passed, we use sys.stdout. """

    pprint_ast(parse(text, mode=mode), indent=indent, file=file)