Some changes in calculator

Author: DanielMSousa

calculator.py

@@ -2,36 +2,59 @@
 
 class Calculadora:
     def __init__(self):
+        self.ponto = True
+        self.error = False
         self.root = Tk()
         self.config_window()
+        self.create_screen()
         self.create_buttons()
         self.root.mainloop()
 
     def config_window(self):
-        self.root.title("Calculator")
+        self.root.title("Calculadora")
         self.root.geometry("400x500")
 
         self.screen_frame = Frame(self.root, bg='#2c2c2c')
-        self.screen_frame.place(relx=0, rely=0, relwidth=1, relheight=0.22)
+        self.screen_frame.place(relx=0, rely=0, relwidth=1, relheight=0.23)
 
-        #The label that shows the results
+        self.button_frame = Frame(self.root)
+        self.button_frame.place(relx=0.001, rely=0.23, relwidth=0.999, relheight=0.77)
+
+    def create_screen(self):
+         #The label that shows the results
         self.equation = ''
         self.eqvar = StringVar()
         self.eqvar.set(self.equation)
 
-        self.resultLabel = Label(self.screen_frame, textvariable=self.eqvar,
+        self.result_frame = Frame(self.screen_frame, bg='#2c2c2c')
+        self.result_frame.place(relx=0, rely=0.5, relwidth=1, relheight=0.5)
+
+        self.resultLabel = Label(self.result_frame, textvariable=self.eqvar,
             bg='#2c2c2c', fg='#ffffff', font=(None, 18), anchor="e")
-        self.resultLabel.pack(side = RIGHT, padx=20, pady=(30, 0))
+        self.resultLabel.pack(side = RIGHT, padx=20, pady=(20, 10))
+
+
+        #Lastequation
+        self.lastvar = StringVar()
+        self.lastvar.set('')
+
+        self.lasteq_frame = Frame(self.screen_frame, bg='#2c2c2c')
+        self.lasteq_frame.place(relx=0, rely=0, relwidth=1, relheight=0.5)
+
+        self.lasteqLabel = Label(self.lasteq_frame, textvariable=self.lastvar,
+            bg='#2c2c2c', fg='#777777', font=(None, 18), anchor="e")
+        self.lasteqLabel.pack(side = RIGHT, padx=20, pady=(30, 0))
 
-        self.button_frame = Frame(self.root)
-        self.button_frame.place(relx=0.001, rely=0.23, relwidth=0.999, relheight=0.77)
 
     def create_buttons(self):
         # Row 1
         self.ac = Button(self.button_frame, text='C', command=self.clean)
-        self.ac.place(relx=0, rely=0, relwidth=0.75, relheight=0.2)
+        self.ac.place(relx=0, rely=0, relwidth=0.5, relheight=0.2)
 
-        self.bdivision = Button(self.button_frame, text='/', command=lambda: self.put_symbol('/'))
+        self.berase = Button(self.button_frame, text='⌫', command=self.erase)
+        self.berase.place(relx=0.5, rely=0, relwidth=0.25, relheight=0.2)
+
+        self.bdivision = Button(self.button_frame, text='/', command=lambda: self.operator(' / '))
         self.bdivision.place(relx=0.75, rely=0, relwidth=0.25, relheight=0.2)
 
         # Row 2
@@ -44,7 +67,7 @@ def create_buttons(self):
         self.b9 = Button(self.button_frame, text='9', command=lambda: self.put_symbol('9'))
         self.b9.place(relx=0.5, rely=0.2, relwidth=0.25, relheight=0.2)
 
-        self.bmulti = Button(self.button_frame, text='*', command=lambda: self.put_symbol('*'))
+        self.bmulti = Button(self.button_frame, text='*', command=lambda: self.operator(' * '))
         self.bmulti.place(relx=0.75, rely=0.2, relwidth=0.25, relheight=0.2)
 
         # Row 3
@@ -57,7 +80,7 @@ def create_buttons(self):
         self.b6 = Button(self.button_frame, text='6', command=lambda: self.put_symbol('6'))
         self.b6.place(relx=0.5, rely=0.4, relwidth=0.25, relheight=0.2)
 
-        self.bsub = Button(self.button_frame, text='-', command=lambda: self.put_symbol('-'))
+        self.bsub = Button(self.button_frame, text='-', command=lambda: self.operator(' - '))
         self.bsub.place(relx=0.75, rely=0.4, relwidth=0.25, relheight=0.2)
 
         #Row 4
@@ -70,7 +93,7 @@ def create_buttons(self):
         self.b3 = Button(self.button_frame, text='3', command=lambda: self.put_symbol('3'))
         self.b3.place(relx=0.5, rely=0.6, relwidth=0.25, relheight=0.2)
 
-        self.bplus = Button(self.button_frame, text='+', command=lambda: self.put_symbol('+'))
+        self.bplus = Button(self.button_frame, text='+', command=lambda: self.operator(' + '))
         self.bplus.place(relx=0.75, rely=0.6, relwidth=0.25, relheight=0.2)
 
         #Row 5 - last one
@@ -83,25 +106,71 @@ def create_buttons(self):
         self.bequal = Button(self.button_frame, text='=', command=self.equal)
         self.bequal.place(relx=0.75, rely=0.8, relwidth=0.25, relheight=0.2)
 
-    def put_symbol(self, symbol):
-        self.equation = self.equation + symbol
+    #updates the screen that shows the results and equations
+    def update_screen(self):
         self.eqvar.set(self.equation)
 
+    #put a symbol at the screen
+    def put_symbol(self, symbol):
+        if(not self.error):
+            self.equation = self.equation + symbol
+            self.update_screen()
+
+    def operator(self, symbol):
+        if(not self.error):
+            self.ponto = True
+            self.put_symbol(symbol)
+
     def put_dot(self):
-        print('I need to check if the dot already exists')
+        if(not self.error):
+            if(self.ponto):
+                self.put_symbol('.')
+                self.ponto = False
+
+    def erase(self):
+        if(not self.error):
+            if self.equation[-1] == '.':
+                self.ponto = True
+            self.equation = self.equation[:-1]
+            self.update_screen()
 
     def clean(self):
         self.equation = ''
-        self.eqvar.set(self.equation)
+        self.error = False
+        self.ponto = True
+        self.lastvar.set('')
+        self.update_screen()
 
     def equal(self):
-        if(self.equation == ''):
-            self.equation = '0'
-        
-        else:
-            self.equation = str(eval(self.equation))
-        
-        self.eqvar.set(self.equation)
-
+        eq = self.equation
+        if(not self.error):
+            if(self.equation == ''):
+                self.equation = '0'
+            
+            else:
+                new_list = []
+                for e in self.equation.split():
+                    a = e.lstrip('0')
+                    if a == '':
+                        new_list.append('0')
+                    else:
+                        new_list.append(a)
+
+                try:
+                    self.equation = str(eval(''.join(new_list)))
+                    
+                except ZeroDivisionError:
+                    if(not self.error):
+                        self.equation = 'Divisão por zero'
+                        self.error = True
+                
+                except SyntaxError:
+                    if(not self.error):
+                        self.equation = 'Expressão mal escrita'
+                        self.error = True
+
+                finally:
+                    self.lastvar.set(eq)
+            self.update_screen()
 
 Calculadora()