stack - Could anyone help me with this python singpath program? -

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first of all, not class. have been working on these 2 programs long time , cannot make heads or tails of it. want past these problems can move onto other lessons. "create function transforms prefix notation postfix notation, , postfix notation prefix notation. function takes 2 arguments. first string of expression without spaces or syntax errors, , second string contains operators. characters not in second string regarded operands. lengths of operators , operands 1, , operators binary operators." ex:

>>> fix_trans('ab33c2c11','abc') '33b211cca'

and convert (reverse) polish notation:

>>> topolish('(3+5)*(7-2)',d,0) '*+35-72'

can provide examples of how far you've gotten this, or methods haven't worked you? also, familiar shunting-yard algorithm?


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