added combine like terms for #39.

mathgenerator/funcs/likeTermCombineFunc.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Fri Oct 23 15:44:50 2020
+
+@author: shyambhu.mukherjee
+"""
+
+from .__init__ import *
+
+
+def likeTermCombineFunc(maxCoef=10, maxExp=20, maxTerms=10):
+    numTerms = random.randint(1, maxTerms)
+    problem = ""
+    solution = ""
+
+    for i in range(numTerms):
+        if i > 0:
+            problem += " + "
+            solution += " + "
+        coefficient = random.randint(1, maxCoef)
+        exponent = random.randint(1, max(numTerms-1,2))
+
+        problem += str(coefficient) + "x^" + str(exponent)
+
+    solution = combineTerms(problem)
+    return problem, solution
+
+
+def combineTerms(string):
+    each_terms = string.split("+")
+    dict_power_wise_terms = {}
+    for i in range(11): dict_power_wise_terms[i] = []
+    for term in each_terms:
+        term = term.split("^")
+        appendee = term[0].split("x")[0]
+        if len(term) == 1:
+            dict_power_wise_terms[1].append(int(appendee))
+        else:
+            dict_power_wise_terms[int(term[1])].append(int(appendee))
+    #print(dict_power_wise_terms)
+    final_string = ''
+    for i in range(11):
+        if len(dict_power_wise_terms[i]) != 0:
+            total = sum(dict_power_wise_terms[i])
+            final_string += str(total)+"x^"+str(i) + " + "
+    final_string = '+'.join(final_string.split("+")[:-1])
+    return final_string
+
+power_rule_integration = Generator("Power Rule Integration", 48, "nx^m=",
+                                   "(n/m)x^(m+1)", powerRuleIntegrationFunc)