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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 ex_varassign(name, expr):
 """Assign an expression into a single variable. The expression may either be an `ast.expr` object or a value to be used as a literal. """

    if not isinstance(expr, ast.expr):
        expr = ex_literal(expr)
    return ast.Assign([ex_lvalue(name)], expr)