Start objecting expression
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Lafrite
parent
decffa6d75
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277
expression.py
277
expression.py
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@ -8,182 +8,185 @@ class Expression(object):
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priority = {"*" : 3, "/": 3, "+": 2, "-":2, "(": 1}
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def __init__(self, exp):
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""" Initiate the expression.
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""" Initiate the expression
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:param exp: the expression. It can be a string or a list of tokens. It can be infix or postfix expression
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"""
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self._tokens = {}
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self._strings = {}
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if type(exp) == list:
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fix = self.get_fix(exp)
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self._tokens[fix] = exp
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elif type(exp) == str:
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tokens = self.parseExp(exp)
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fix = self.get_fix(tokens)
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self._tokens[fix] = tokens
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self._strings[fix] = exp
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self._exp = exp
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def simplify(self):
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""" Generator which return steps for computing the expression """
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if self._exp == 0:
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yield "Zero!"
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else:
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raise ValueError("The expression needs to be a string or a list of token")
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self.children = Expression(self._exp - 1)
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yield "num: " + str(self._exp)
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yield self.children.simplify().next()
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# ---------------------
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# String parsing
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## ---------------------
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## String parsing
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# @classmethod ????
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def parseExp(self, exp):
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""" Parse the expression, ie tranform a string into a list of tokens
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## @classmethod ????
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#def parseExp(self, exp):
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# """ Parse the expression, ie tranform a string into a list of tokens
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:param exp: The expression (a string)
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:returns: list of token
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# :param exp: The expression (a string)
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# :returns: list of token
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"""
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return exp.split(" ")
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# """
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# return exp.split(" ")
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# ---------------------
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# "fix" recognition
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## ---------------------
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## "fix" recognition
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def get_fix(self, tokens):
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""" Give the "fix" of an expression
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infix -> A + B
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prefix -> + A B
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postfix -> A B +
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#def get_fix(self, tokens):
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# """ Give the "fix" of an expression
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# infix -> A + B
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# prefix -> + A B
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# postfix -> A B +
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:param exp: the expression (list of token)
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:returns: the "fix" (infix, postfix, prefix)
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# :param exp: the expression (list of token)
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# :returns: the "fix" (infix, postfix, prefix)
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"""
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if tokens[0] in "+-*/":
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return "prefix"
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elif token[0] not in "+-*/" ans token[1] not in "+-*/":
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return "postfix"
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else:
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return "infix"
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# """
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# if tokens[0] in "+-*/":
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# return "prefix"
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# elif token[0] not in "+-*/" ans token[1] not in "+-*/":
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# return "postfix"
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# else:
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# return "infix"
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# ----------------------
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# Expressions - tokens getters
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## ----------------------
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## Expressions - tokens getters
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def tokens(self, fix = "infix"):
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"""Get the list of tokens with the wanted fix
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#def tokens(self, fix = "infix"):
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# """Get the list of tokens with the wanted fix
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:param fix: the fix wanted (infix default)
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:returns: list of tokens
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# :param fix: the fix wanted (infix default)
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# :returns: list of tokens
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"""
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# Si ce fix n'a pas encore été enregistré
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if fix not in self._tokens:
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# Il peut venir de la version string
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if fix in self._string:
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self._tokens[fix] = self.parseExp(self._string[fix])
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# Sinon il faut le calculer à partir d'une autre forme
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else:
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fix_transfo = "to" + fix.capitalize()
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getattr(self,fix_transfo)()
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# """
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# # Si ce fix n'a pas encore été enregistré
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# if fix not in self._tokens:
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# # Il peut venir de la version string
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# if fix in self._string:
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# self._tokens[fix] = self.parseExp(self._string[fix])
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# # Sinon il faut le calculer à partir d'une autre forme
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# else:
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# fix_transfo = "to" + fix.capitalize()
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# getattr(self,fix_transfo)()
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return self._tokens[fix]
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# return self._tokens[fix]
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##### On en est là,il faudra faire attention à bien vérifier ce que les "to..." enregistre (string ou tokens)
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###### On en est là,il faudra faire attention à bien vérifier ce que les "to..." enregistre (string ou tokens)
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def string(self, fix = "infix"):
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"""Get the string with the wanted fix
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#def string(self, fix = "infix"):
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# """Get the string with the wanted fix
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:param fix: the fix wanted (infix default)
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:returns: the string representing the expression
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# :param fix: the fix wanted (infix default)
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# :returns: the string representing the expression
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"""
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# Si ce fix n'a pas encore été enregistré
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if fix not in self._string:
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# Il peut venir de la version string
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if fix in self._tokens:
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self._string[fix] = self.parseExp(self._string[fix])
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# Sinon il faut le calculer à partir d'une autre forme
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else:
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fix_transfo = "to" + fix.capitalize()
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getattr(self,fix_transfo)()
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# """
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# # Si ce fix n'a pas encore été enregistré
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# if fix not in self._string:
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# # Il peut venir de la version string
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# if fix in self._tokens:
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# self._string[fix] = self.parseExp(self._string[fix])
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# # Sinon il faut le calculer à partir d'une autre forme
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# else:
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# fix_transfo = "to" + fix.capitalize()
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# getattr(self,fix_transfo)()
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return self._string[fix]
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# ----------------------
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# "fix" tranformations
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# return self._string[fix]
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#
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## ----------------------
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## "fix" tranformations
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def toPostfix(self):
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""" Transorm the expression into postfix form using the infix form"""
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pass
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#def toPostfix(self):
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# """ Transorm the expression into postfix form using the infix form"""
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# pass
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def toInfix(self):
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""" Tranform the expression into infix form using postfix form"""
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pass
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#def toInfix(self):
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# """ Tranform the expression into infix form using postfix form"""
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# pass
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# ---------------------
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# Tools for placing parenthesis in infix notation
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## ---------------------
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## Tools for placing parenthesis in infix notation
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def needPar(operande, operator, posi = "after"):
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""" Says whether or not the operande needs parenthesis
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#def needPar(operande, operator, posi = "after"):
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# """ Says whether or not the operande needs parenthesis
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:param operande: the operande
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:param operator: the operator
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:param posi: "after"(default) if the operande will be after the operator, "before" othewise
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:returns: bollean
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"""
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if isNumber(operande) and "-" in operande:
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return 1
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elif not isNumber(operande):
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# Si c'est une grande expression ou un chiffre négatif
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stand_alone = get_main_op(operande)
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# Si la priorité de l'operande est plus faible que celle de l'opérateur
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minor_priority = self.priority[get_main_op(operande)] < self.priority[operator]
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# Si l'opérateur est -/ pour after ou juste / pour before
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special = (operator in "-/" and posi == "after") or (operator in "/" and posi == "before")
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# :param operande: the operande
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# :param operator: the operator
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# :param posi: "after"(default) if the operande will be after the operator, "before" othewise
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# :returns: bollean
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# """
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# if isNumber(operande) and "-" in operande:
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# return 1
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# elif not isNumber(operande):
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# # Si c'est une grande expression ou un chiffre négatif
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# stand_alone = get_main_op(operande)
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# # Si la priorité de l'operande est plus faible que celle de l'opérateur
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# minor_priority = self.priority[get_main_op(operande)] < self.priority[operator]
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# # Si l'opérateur est -/ pour after ou juste / pour before
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# special = (operator in "-/" and posi == "after") or (operator in "/" and posi == "before")
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return stand_alone and (minor_priority or special)
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else:
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return 0
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# J'aime pas bien cette endroit faudrait que ce soit une méthode qui s'applique uniquement à l'expression en question (self) pas à n'importe quel string, ça serait plus propre.
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def get_main_op(exp):
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""" Gives the main operation of the expression
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# return stand_alone and (minor_priority or special)
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# else:
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# return 0
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#
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# J'#aime pas bien cette endroit faudrait que ce soit une méthode qui s'applique uniquement à l'expression en question (self) pas à n'importe quel string, ça serait plus propre.
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#def get_main_op(exp):
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# """ Gives the main operation of the expression
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:param exp: the expression
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:returns: the main operation (+, -, * or /) or 0 if the expression is only one element
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# :param exp: the expression
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# :returns: the main operation (+, -, * or /) or 0 if the expression is only one element
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"""
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parStack = Stack()
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tokenList = exp.split(" ")
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# """
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# parStack = Stack()
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# tokenList = exp.split(" ")
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if len(tokenList) == 1:
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# Si l'expression n'est qu'un élément
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return 0
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# if len(tokenList) == 1:
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# # Si l'expression n'est qu'un élément
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# return 0
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main_op = []
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# main_op = []
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for token in tokenList:
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if token == "(":
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parStack.push(token)
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elif token == ")":
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parStack.pop()
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elif token in "+-*/" and parStack.isEmpty():
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main_op.append(token)
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# for token in tokenList:
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# if token == "(":
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# parStack.push(token)
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# elif token == ")":
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# parStack.pop()
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# elif token in "+-*/" and parStack.isEmpty():
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# main_op.append(token)
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return min(main_op, key = lambda s: priority[s])
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# return min(main_op, key = lambda s: priority[s])
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# ---------------------
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# Computing the expression
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## ---------------------
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## Computing the expression
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def compute(self):
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""" Recursive method for computing as a student the expression
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:returns: list of steps needed to reach the result
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#def compute(self):
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# """ Recursive method for computing as a student the expression
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# :returns: list of steps needed to reach the result
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"""
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pass
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def doMath(op, op1, op2):
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"""Compute "op1 op op2"
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# """
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# pass
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#
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#def doMath(op, op1, op2):
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# """Compute "op1 op op2"
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:param op: operator
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:param op1: first operande
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:param op2: second operande
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:returns: string representing the result
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# :param op: operator
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# :param op1: first operande
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# :param op2: second operande
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# :returns: string representing the result
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"""
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return str(eval(op1 + op + op2))
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# """
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# return str(eval(op1 + op + op2))
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if __name__ == '__main__':
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a = Expression(10)
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for i in a.simplify():
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print(i)
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# -----------------------------
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# Reglages pour 'vim'
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@ -0,0 +1,191 @@
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#!/usr/bin/env python
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# encoding: utf-8
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class Expression(object):
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"""A calculus expression. Today it can andle only expression with numbers later it will be able to manipulate unknown"""
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priority = {"*" : 3, "/": 3, "+": 2, "-":2, "(": 1}
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def __init__(self, exp):
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""" Initiate the expression.
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:param exp: the expression. It can be a string or a list of tokens. It can be infix or postfix expression
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"""
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self._tokens = {}
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self._strings = {}
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if type(exp) == list:
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fix = self.get_fix(exp)
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self._tokens[fix] = exp
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elif type(exp) == str:
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tokens = self.parseExp(exp)
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fix = self.get_fix(tokens)
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self._tokens[fix] = tokens
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self._strings[fix] = exp
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else:
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raise ValueError("The expression needs to be a string or a list of token")
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# ---------------------
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# String parsing
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# @classmethod ????
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def parseExp(self, exp):
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""" Parse the expression, ie tranform a string into a list of tokens
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:param exp: The expression (a string)
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:returns: list of token
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"""
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return exp.split(" ")
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# ---------------------
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# "fix" recognition
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def get_fix(self, tokens):
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""" Give the "fix" of an expression
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infix -> A + B
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prefix -> + A B
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postfix -> A B +
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:param exp: the expression (list of token)
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:returns: the "fix" (infix, postfix, prefix)
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"""
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if tokens[0] in "+-*/":
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return "prefix"
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elif token[0] not in "+-*/" ans token[1] not in "+-*/":
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return "postfix"
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else:
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return "infix"
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# ----------------------
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# Expressions - tokens getters
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def tokens(self, fix = "infix"):
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"""Get the list of tokens with the wanted fix
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:param fix: the fix wanted (infix default)
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:returns: list of tokens
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"""
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# Si ce fix n'a pas encore été enregistré
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if fix not in self._tokens:
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# Il peut venir de la version string
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if fix in self._string:
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self._tokens[fix] = self.parseExp(self._string[fix])
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# Sinon il faut le calculer à partir d'une autre forme
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else:
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fix_transfo = "to" + fix.capitalize()
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getattr(self,fix_transfo)()
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return self._tokens[fix]
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##### On en est là,il faudra faire attention à bien vérifier ce que les "to..." enregistre (string ou tokens)
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def string(self, fix = "infix"):
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"""Get the string with the wanted fix
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:param fix: the fix wanted (infix default)
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:returns: the string representing the expression
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"""
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# Si ce fix n'a pas encore été enregistré
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if fix not in self._string:
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# Il peut venir de la version string
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if fix in self._tokens:
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self._string[fix] = self.parseExp(self._string[fix])
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# Sinon il faut le calculer à partir d'une autre forme
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else:
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fix_transfo = "to" + fix.capitalize()
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getattr(self,fix_transfo)()
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return self._string[fix]
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# ----------------------
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# "fix" tranformations
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def toPostfix(self):
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""" Transorm the expression into postfix form using the infix form"""
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pass
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def toInfix(self):
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""" Tranform the expression into infix form using postfix form"""
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pass
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# ---------------------
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# Tools for placing parenthesis in infix notation
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def needPar(operande, operator, posi = "after"):
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""" Says whether or not the operande needs parenthesis
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:param operande: the operande
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:param operator: the operator
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:param posi: "after"(default) if the operande will be after the operator, "before" othewise
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:returns: bollean
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"""
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if isNumber(operande) and "-" in operande:
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return 1
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elif not isNumber(operande):
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# Si c'est une grande expression ou un chiffre négatif
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stand_alone = get_main_op(operande)
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# Si la priorité de l'operande est plus faible que celle de l'opérateur
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minor_priority = self.priority[get_main_op(operande)] < self.priority[operator]
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# Si l'opérateur est -/ pour after ou juste / pour before
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special = (operator in "-/" and posi == "after") or (operator in "/" and posi == "before")
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return stand_alone and (minor_priority or special)
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else:
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return 0
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# J'aime pas bien cette endroit faudrait que ce soit une méthode qui s'applique uniquement à l'expression en question (self) pas à n'importe quel string, ça serait plus propre.
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def get_main_op(exp):
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""" Gives the main operation of the expression
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:param exp: the expression
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:returns: the main operation (+, -, * or /) or 0 if the expression is only one element
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"""
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parStack = Stack()
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tokenList = exp.split(" ")
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if len(tokenList) == 1:
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# Si l'expression n'est qu'un élément
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return 0
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main_op = []
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for token in tokenList:
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if token == "(":
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parStack.push(token)
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elif token == ")":
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parStack.pop()
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elif token in "+-*/" and parStack.isEmpty():
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main_op.append(token)
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|
||||
return min(main_op, key = lambda s: priority[s])
|
||||
|
||||
# ---------------------
|
||||
# Computing the expression
|
||||
|
||||
def compute(self):
|
||||
""" Recursive method for computing as a student the expression
|
||||
:returns: list of steps needed to reach the result
|
||||
|
||||
"""
|
||||
pass
|
||||
|
||||
def doMath(op, op1, op2):
|
||||
"""Compute "op1 op op2"
|
||||
|
||||
:param op: operator
|
||||
:param op1: first operande
|
||||
:param op2: second operande
|
||||
:returns: string representing the result
|
||||
|
||||
"""
|
||||
return str(eval(op1 + op + op2))
|
||||
|
||||
# -----------------------------
|
||||
# Reglages pour 'vim'
|
||||
# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
|
||||
# cursor: 16 del
|
||||
Loading…
Reference in New Issue