formal (which should be called polynom...) are ok.No mult yet

This commit is contained in:
lafrite 2014-01-17 20:17:49 +01:00
parent 999fde1c51
commit 039f27c4fc
4 changed files with 259 additions and 36 deletions

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@ -4,6 +4,8 @@
from generic import Stack, flatten_list, expand_list
from fraction import Fraction
from render import txt_render, post2in_fix, tex_render
from formal import FormalExp
from formal import FormalExp
class Expression(object):
"""A calculus expression. Today it can andle only expression with numbers later it will be able to manipulate unknown"""
@ -32,7 +34,7 @@ class Expression(object):
def render(self, render = lambda x:str(x)):
""" Same as __str__ but accept render as argument
@param render: function which render the list of token (postfix form) to string
:param render: function which render the list of token (postfix form) to string
"""
# TODO: I don't like the name of this method |ven. janv. 17 12:48:14 CET 2014
@ -44,7 +46,7 @@ class Expression(object):
def simplify(self, render = lambda x:str(x)):
""" Generator which return steps for computing the expression
@param render: function which render the list of token (postfix form now) to string
:param render: function which render the list of token (postfix form now) to string
"""
if not self.can_go_further():
@ -123,8 +125,10 @@ class Expression(object):
for character in exp:
if character.isdigit():
# for "big" numbers (like 2345)
if type(tokens[-1]) == int:
tokens[-1] = tokens[-1]*10 + int(character)
# Special case for "-" at the begining of an expression or before "("
elif tokens[-1] == "-" and \
str(tokens[-2]) in " (":
@ -133,16 +137,29 @@ class Expression(object):
tokens.append(int(character))
elif character.isalpha():
if str(tokens[-1]).isalpha():
tokens[-1] += character
# If "3x", ")x" or "yx"
if self.isNumber(tokens[-1]) \
or tokens[-1] == ")" \
or type(tokens[-1]) == FormalExp:
tokens.append("*")
tokens.append(FormalExp(letter = character))
# Special case for "-" at the begining of an expression or before "("
elif tokens[-1] == "-" \
or str(tokens[-2]) in " (":
tokens[-1] = - FormalExp(letter = character)
else:
tokens.append(character)
tokens.append(FormalExp(letter = character))
elif character in "+-*/)":
tokens.append(character)
elif character in "(":
if self.isNumber(tokens[-1]) or tokens[-1] == ")":
# If "3(", ")(" or "x("
if self.isNumber(tokens[-1]) \
or tokens[-1] == ")" \
or type(tokens[-1]) == FormalExp:
tokens.append("*")
tokens.append(character)
@ -278,13 +295,18 @@ class Expression(object):
:returns: string representing the result
"""
operations = {"+": "__add__", "-": "__sub__", "*": "__mul__"}
if op == "/":
ans = [Fraction(op1, op2)]
ans += ans[0].simplify()
return ans
else:
return getattr(op1,operations[op])(op2)
if type(op2) != int:
operations = {"+": "__radd__", "-": "__rsub__", "*": "__rmul__"}
return getattr(op2,operations[op])(op1)
else:
operations = {"+": "__add__", "-": "__sub__", "*": "__mul__"}
return getattr(op1,operations[op])(op2)
## ---------------------
## Recognize numbers and operators
@ -299,7 +321,7 @@ class Expression(object):
"""
return type(exp) == int or \
type(exp) == Fraction or \
exp.isalpha()
type(exp) == FormalExp
@staticmethod
def isOperator(exp):
@ -322,17 +344,17 @@ def test(exp):
print("\n")
if __name__ == '__main__':
exp = "1 + 3 * 5"
test(exp)
#exp = "1 + 3 * 5"
#test(exp)
#exp = "2 * 3 * 3 * 5"
#test(exp)
exp = "2 * 3 + 3 * 5"
test(exp)
#exp = "2 * 3 + 3 * 5"
#test(exp)
exp = "2 * ( 3 + 4 ) + 3 * 5"
test(exp)
#exp = "2 * ( 3 + 4 ) + 3 * 5"
#test(exp)
#exp = "2 * ( 3 + 4 ) + ( 3 - 4 ) * 5"
#test(exp)
@ -352,25 +374,29 @@ if __name__ == '__main__':
#exp = "( 2 + 5 ) * ( 3 * 4 )"
#test(exp)
exp = "( 2 + 5 - 1 ) / ( 3 * 4 )"
test(exp)
#exp = "( 2 + 5 - 1 ) / ( 3 * 4 )"
#test(exp)
exp = "( 2 + 5 ) / ( 3 * 4 ) + 1 / 12"
test(exp)
#exp = "( 2 + 5 ) / ( 3 * 4 ) + 1 / 12"
#test(exp)
exp = "( 2+ 5 )/( 3 * 4 ) + 1 / 2"
test(exp)
#exp = "( 2+ 5 )/( 3 * 4 ) + 1 / 2"
#test(exp)
exp="(-2+5)/(3*4)+1/12+5*5"
test(exp)
#exp="(-2+5)/(3*4)+1/12+5*5"
#test(exp)
exp="-2*4(12 + 1)(3-12)"
test(exp)
exp="-2*a(12 + 1)(3-12)"
exp="-2+a+(12 + 1)(3-12) + 34a"
test(exp)
e = Expression(exp)
print(e)
#exp="-2*b+a(12 + 1)(3-12)"
#test(exp)
# TODO: The next one doesn't work |ven. janv. 17 14:56:58 CET 2014
#exp="-2*(-a)(12 + 1)(3-12)"
#e = Expression(exp)

128
formal.py Normal file
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@ -0,0 +1,128 @@
#!/usr/bin/env python
# encoding: utf-8
from fraction import Fraction
from generic import add_in_dict, remove_in_dict
import re
class FormalExp(object):
"""A formal expression (similare to Symbol in Sympy"""
def __init__(self, coef = {}, letter = ""):
"""Initiat the formal expression
:param coef: the dictionary representing the expression
:param letter: minimum expression, a letter
"""
if coef != {} and letter != "":
raise ValueError("A FormalExp can't be initiate with dict_exp and a letter")
elif letter != "":
self._letter = letter
self._coef = {letter: 1}
elif coef != {}:
self._coef = coef
else:
raise ValueError("FormalExp needs a letter or dictionary of coeficients")
if len(self) != 1:
self.mainOp = "+"
def master_coef(self):
"""Return the master coefficient
/!\ may not work pretty well if there is more than one indeterminate
:returns: a_n
"""
pattern = "\w\*\*(\d*)"
finder = re.compile(pattern)
power = {}
for (k,v) in self._coef.items():
if k=="":
power[0] = v
else:
p = finder.findall(k)
if p == []:
power[1] = v
else:
power[int(p[0])] = v
m_power = max(power)
return power[m_power]
def __add__(self, other):
if type(other) in [int, Fraction]:
d = {"":other}
elif type(other) == FormalExp:
d = other._coef
else:
raise ValueError("Can't add {type} with FormalExp".format(type=type(other)))
d = add_in_dict(self._coef, d)
d = remove_in_dict(d)
if list(d.keys()) == ['']:
return [d['']]
else:
return [FormalExp(d)]
def __radd__(self, other):
return self + other
def __sub__(self, other):
o_tmp = -other
return self + o_tmp
def __neg__(self):
d = {}
for k,v in self._coef.items():
d[k] = -v
return FormalExp(d)
def __mul__(self, other):
pass
def __rmul__(self, other):
pass
def __div__(self, other):
pass
def __pow__(self, other):
pass
def __len__(self):
return len(list(self._coef.keys()))
def __str__(self):
return " + ".join([str(v) + str(k) for k,v in self._coef.items()])
if __name__ == '__main__':
#fe1 = FormalExp({"x": 1, "":2})
#print(fe1)
#fe2 = FormalExp({"x**12": 5, "":2})
#print(fe2)
#fe3 = fe1 + fe2
#for s in fe3:
# print(s)
#fe4 = fe1 + 2
#for s in fe4:
# print(s)
#print(fe1.master_coef())
#print(fe2.master_coef())
#print(fe3[0].master_coef())
#print(fe4[0].master_coef())
fe = FormalExp(letter = "a")
fe_ = -2 + fe
print(fe_[0])
# -----------------------------
# Reglages pour 'vim'
# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
# cursor: 16 del

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@ -99,6 +99,54 @@ def expand_list(list_list):
ans = [list_list]
return ans
def add_in_dict(dict1, dict2):
"""Merge dictionary keys and add the content from dict1 and dict2
:param dict1: first dictionary
:param dict2: second dictionary
:returns: merged and added dictionary
>>> add_in_dict({'a':1, 'b':2}, {'c':3, 'd': 4}) == {'d': 4, 'a': 1, 'c': 3, 'b': 2}
True
>>> add_in_dict({'a':1, 'b':2}, {'a':3, 'b': 4}) == {'a': 4, 'b': 6}
True
>>> add_in_dict({'a':1, 'b':2}, {'a':3, 'c': 4}) == {'a': 4, 'b': 2, 'c': 4}
True
"""
new_dict = {}
new_dict.update(dict1)
for (k,v) in dict2.items():
if k in new_dict.keys():
new_dict[k] += v
else:
new_dict[k] = v
return new_dict
def remove_in_dict(d, value = 0):
""" In a dictionary, remove keys which have certain value
:param d: the dictionary
:param value: value to remove
:returns: new dictionary whithout unwanted value
>>> remove_in_dict({'b': 1, 'a': 0}) == {'b': 1}
True
>>> remove_in_dict({'b': 1, 'a': 0}, 1) == {'a': 0}
True
"""
new_dict = {}
for (k,v) in d.items():
if v != value:
new_dict[k] = v
return new_dict
if __name__ == '__main__':
import doctest
doctest.testmod()
# -----------------------------
# Reglages pour 'vim'
# vim:set autoindent expandtab tabstop=4 shiftwidth=4:

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@ -3,6 +3,7 @@
from generic import Stack,flatten_list
from fraction import Fraction
from formal import FormalExp
@ -16,7 +17,7 @@ class Render(object):
PRIORITY = {"*" : 3, "/": 3, "+": 2, "-":2, "(": 1}
def __init__(self, op_infix = {}, op_postfix = {}, other = {}, join = " ", type_render = {int: str, Fraction: str, str: str}):
def __init__(self, op_infix = {}, op_postfix = {}, other = {}, join = " ", type_render = {int: str, Fraction: str, FormalExp: str}):
"""Initiate the render
@param op_infix: the dictionnary of infix operator with how they have to be render
@ -71,11 +72,12 @@ class Render(object):
else:
operandeStack.push(token)
# Manip pour gerer les cas de listes imbriquées dans d'autres listes
infix_tokens = operandeStack.pop()
if type(infix_tokens) == list or type(infix_tokens) == flist:
infix_tokens = flatten_list(infix_tokens)
elif self.isNumber(infix_tokens):
elif self.isNumerande(infix_tokens):
infix_tokens = [infix_tokens]
if self.join:
@ -84,13 +86,13 @@ class Render(object):
return infix_tokens
def render_from_type(self, op):
""" If the op is a number, it transforms it with type_render conditions
""" If the op is a numerande, it transforms it with type_render conditions
:param op: the operator
:returns: the op transformed if it's necessary
"""
if self.isNumber(op):
if self.isNumerande(op):
return self.type_render[type(op)](op)
else:
return op
@ -108,9 +110,17 @@ class Render(object):
:returns: bollean
"""
if self.isNumber(operande) \
and type(operande) != str \
and operande < 0:
return 1
elif type(operande) == FormalExp:
if operator in ["*", "/"]:
if len(operande) > 1 \
or operande.master_coef() < 0:
return 1
else:
return 0
elif not self.isNumber(operande):
# Si c'est une grande expression ou un chiffre négatif
stand_alone = self.get_main_op(operande)
@ -155,17 +165,28 @@ class Render(object):
@staticmethod
def isNumber( exp):
"""Check if the expression can be a number which means that it is not a operator
"""Check if the expression can be a number which means int or Fraction
:param exp: an expression
:returns: True if the expression can be a number and false otherwise
"""
return type(exp) == int or \
type(exp) == Fraction or \
(type(exp) == str and exp.isalpha())
return type(exp) == int \
or type(exp) == Fraction
#return type(exp) == int or type(exp) == Fraction
@staticmethod
def isNumerande(exp):
"""Check if the expression can be a numerande (not an operator)
:param exp: an expression
:returns: True if the expression can be a number and false otherwise
"""
return type(exp) == int \
or type(exp) == Fraction \
or type(exp) == FormalExp
def isOperator(self, exp):
"""Check if the expression is in self.operators
@ -202,9 +223,9 @@ post2in_fix = Render(p2i_infix, p2i_postfix, p2i_other, join = False)
# A latex render
def texSlash(op1, op2):
if not Render.isNumber(op1) and op1[0] == "(" and op1[-1] == ")":
if not Render.isNumerande(op1) and op1[0] == "(" and op1[-1] == ")":
op1 = op1[1:-1]
if not Render.isNumber(op2) and op2[0] == "(" and op2[-1] == ")":
if not Render.isNumerande(op2) and op2[0] == "(" and op2[-1] == ")":
op2 = op2[1:-1]
return ["\\frac{" , op1 , "}{" , op2 , "}"]
@ -214,7 +235,7 @@ def texFrac(frac):
tex_infix = {"+": " + ", "-": " - ", "*": " \\times "}
tex_postfix = {"/": texSlash}
tex_other = {"(": "(", ")": ")"}
tex_type_render = {int: str, Fraction: texFrac, str: str}
tex_type_render = {int: str, Fraction: texFrac, FormalExp: str}
tex_render = Render(tex_infix, tex_postfix, tex_other, type_render = tex_type_render)