140 lines
4.1 KiB
Python
140 lines
4.1 KiB
Python
#!/usr/bin/env python
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# encoding: utf-8
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from random import randint
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from .expression import Expression
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from .renders import tex_render, txt_render
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import re
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class RdExpression(object):
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"""A generator of random expression builder"""
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def __init__(self, form, conditions = []):
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"""Initiate the generator
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:param form: the form of the expression (/!\ variables need to be in brackets {})
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:param conditions: condition on variables (/!\ variables need to be in brackets {})
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"""
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self._form = form
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self._conditions = conditions
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self._letters = self.get_letters()
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self._gene_varia = {}
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self._gene_2replaced= {}
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def get_2replaced(self):
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"""Get elements of self._form which will have to be replaced
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:returns: set for elements which have to be replaced
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"""
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pattern = "\{(.*?)\}" #select inside {} non greedy way
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varia = re.findall(pattern, self._form)
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varia = set(varia)
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self._2replaced = varia
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return varia
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def get_letters(self):
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"""Find letters in the form
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:returns: list of letters
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"""
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v2replaced = self.get_2replaced()
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varia = set()
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pattern = "([a-zA-Z]+)"
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for v in v2replaced:
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lvar = set(re.findall(pattern, v))
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varia = varia | lvar
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return varia
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def __call__(self, val_min = -10, val_max = 10, render = tex_render):
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"""RdExpression once it is initiate act like a function which create random expressions.
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:param val_min: minimum value random generation
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:param val_max: maximum value random generation
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:param render: Render of the expression (returns an Expression by default)
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:returns: an formated random expression
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"""
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return render(self.raw_exp(val_min, val_max).postfix_tokens)
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def raw_exp(self, val_min = -10, val_max = 10):
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"""Same as __call_ but returns an Expression object
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:param val_min: minimum value random generation
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:param val_max: maximum value random generation
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:returns: an random Expression object
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"""
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self.gene_varia(val_min, val_max)
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while not(self.val_conditions()):
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self.gene_varia(val_min, val_max)
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exp = self._form.format(**self._gene_2replaced)
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return Expression(exp)
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def gene_varia(self, val_min = -10, val_max = 10):
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"""RAndomly generates variables/letters
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"""
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for l in self._letters:
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self._gene_varia[l] = randint(val_min, val_max)
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while self._gene_varia[l] == 0:
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self._gene_varia[l] = randint(val_min, val_max)
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for e in self._2replaced:
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self._gene_2replaced[e] = eval(e, globals(), self._gene_varia)
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def val_conditions(self):
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"""Tells whether or not conditions are validates
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:returns: boolean
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"""
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if self._conditions != []:
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return eval(" and ".join(self._conditions).format(**self._gene_varia))
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else:
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return True
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def desc_rdExp(rdExp):
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print("--------------------")
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print("form: ",rdExp._form)
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print("Conditions: ",rdExp._conditions)
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print("Letters: ", rdExp._letters)
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print("2replaced: ", rdExp._2replaced)
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print("Call : ", rdExp(render = tex_render))
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print("Gene varia: ", rdExp._gene_varia)
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print("Gene 2replaced: ", rdExp._gene_2replaced)
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print('')
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if __name__ == '__main__':
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#form = "{a}*-14 / (2*{b}) : -23 / 4"
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#cond = ["{a} + {b} in [1, 2, 3, 4, 5]", "{a} not in [0,1]", "{b} not in [0,1]"]
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#rdExp1 = RdExpression(form, cond)
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#desc_rdExp(rdExp1)
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#rdExp2 = RdExpression(form)
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#desc_rdExp(rdExp2)
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#form = "{a+a/10}x + {a} + 2*{b}"
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#cond = ["{a} + {b} in [1, 2, 3, 4, 5]", "{a} not in [0,1]", "{b} not in [0,1]"]
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#rdExp3 = RdExpression(form)
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#desc_rdExp(rdExp3)
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form1 = "{a**2}x^2 + {2*a*b}x + {b**2}"
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cond1 = []
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rdExp1 = RdExpression(form1, cond1)
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desc_rdExp(rdExp1)
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# -----------------------------
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# Reglages pour 'vim'
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# vim:set autoindent expandtab tabstop=4 shiftwidth=4:
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# cursor: 16 del
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