{"id":7443,"date":"2020-09-27T10:39:43","date_gmt":"2020-09-27T08:39:43","guid":{"rendered":"https:\/\/pythonprogramming.altervista.org\/?p=7443"},"modified":"2020-09-27T21:30:18","modified_gmt":"2020-09-27T19:30:18","slug":"solve-a-proportion-with-python-teach-math-with-python-1","status":"publish","type":"post","link":"https:\/\/pythonprogramming.altervista.org\/solve-a-proportion-with-python-teach-math-with-python-1\/","title":{"rendered":"Solve a proportion with Python – Teach math with Python – part 1"},"content":{"rendered":"

A little class to solve proportions:<\/p>\n

# python_math 1\r\n# proportions\r\n\r\nclass Prop:\r\n    def __init__(self, prop):\r\n        '''This is how you put the argument e1 : e2 = m1 : m2 \r\n        ie: 12 : 3 = 36:9\r\n        '''\r\n        self.proportion = prop\r\n        prop = prop.replace(\"=\", \":\")\r\n        self.prop = e1, m1, m2, e2 = prop.split(\":\")\r\n        for n, x in enumerate(self.prop):\r\n            if x.strip() == \"x\":\r\n                self.prop[n] = None\r\n            else:\r\n                self.prop[n] = int(x)\r\n        e1, m1, m2, e2 = self.prop\r\n        self.e1 = e1\r\n        self.e2 = e2\r\n        self.m1 = m1\r\n        self.m2 = m2\r\n\r\n    def calculate_x(self):\r\n        \"Call this from the istance to find the incognito\"\r\n        print(f\"The result of '{self.proportion}' is \", end=\"\")\r\n        if self.e1 is None:\r\n            res = self.m1 * self.m2 \/ self.e2\r\n            return res\r\n        elif self.e2 is None:\r\n            res = self.m1 * self.m2 \/ self.e1\r\n            return res\r\n        elif self.m1 is None:\r\n            res = self.e1 * self.e2 \/ self.m2\r\n            return res \r\n        elif self.m2 is None:\r\n            res = self.e1 * self.e2 \/ self.m1\r\n            return res\r\n        print(res)\r\n\r\n\r\n\r\np1 = Prop(\"12 : 3 = 36 : x\")\r\nprint(p1.calculate_x())\r\n<\/pre>\n
The result<\/p>\n
The result of '12 : 3 = 36 : x' is 9.0\r\n>>><\/pre>\n
Fully commented code<\/h2>\n
If you want to see what the code does without having to guess by the code, see this fully commented code version of the one above:<\/p>\n
# python_math 1\r\n# proportions\r\n\r\nclass Prop:\r\n    def __init__(self, prop):\r\n        '''This is how you put the argument e1 : e2 = m1 : m2 \r\n        ie: 12 : 3 = 36:9\r\n        '''\r\n        self.proportion = prop\r\n        # replace = with :\r\n        prop = prop.replace(\"=\", \":\")\r\n        # create a list with the numbers, splitting by the ':'\r\n        self.prop = prop.split(\":\")\r\n        # converts strings into integers and x to None\r\n        for n, x in enumerate(self.prop):\r\n            if x.strip() == \"x\":\r\n                self.prop[n] = None\r\n            else:\r\n                self.prop[n] = int(x)\r\n        # memorize in memorable names the extrem and medium terms\r\n        e1, m1, m2, e2 = self.prop\r\n        self.e1 = e1\r\n        self.e2 = e2\r\n        self.m1 = m1\r\n        self.m2 = m2\r\n\r\n    def calculate_x(self):\r\n        \"Call this from the istance to find the incognito\"\r\n        print(f\"The result of '{self.proportion}' is \", end=\"\")\r\n        # Depending on what is None (incognito), it finds it with the other 3\r\n        if self.e1 is None:\r\n            res = self.m1 * self.m2 \/ self.e2\r\n            return res\r\n        elif self.e2 is None:\r\n            res = self.m1 * self.m2 \/ self.e1\r\n            return res\r\n        elif self.m1 is None:\r\n            res = self.e1 * self.e2 \/ self.m2\r\n            return res \r\n        elif self.m2 is None:\r\n            res = self.e1 * self.e2 \/ self.m1\r\n            return res\r\n        print(res)\r\n\r\n\r\n# First you create the istance of Prop with a string containing the proposition\r\np1 = Prop(\"12 : 3 = 36 : x\")\r\n# Then you get the solution with calculate_x (method of Prop class)\r\nprint(p1.calculate_x())\r\n<\/pre>\n
 <\/p>\n
Video tutorial about this script<\/h2>\n