diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ba0430d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+__pycache__/
\ No newline at end of file
diff --git a/expression.py b/expression.py
index 9c4361d..b70ceac 100644
--- a/expression.py
+++ b/expression.py
@@ -1,23 +1 @@
 from lexer import Token
-
-class Expression:
-
-    def __init__(self, val, gauche=None, droite=None):
-        if Token.NUMBER.search(str(val)) is not None and (gauche != None or droite != None):
-            raise AttributeError("gauche et droite ne peuvent pas exister si val est un nombre")
-        self.val = val
-        self.gauche = gauche
-        self.droite = droite
-
-    def evalue(self):
-        if self.val == Token.OPERAND_ADDITION:
-            return self.gauche.evalue() + self.droite.evalue()
-        elif self.val == Token.OPERAND_MULTIPLICATION:
-            return self.gauche.evalue() * self.droite.evalue()
-        else:
-            return int(self.val)
-
-    def __str__(self):
-        if Token.NUMBER.match(str(self.val)) != None:
-            return str(self.val)
-        return "(" + str(self.gauche.__str__()) + str(self.val) + str(self.droite.__str__()) + ")"
diff --git a/infixe.py b/infixe.py
new file mode 100644
index 0000000..2739d86
--- /dev/null
+++ b/infixe.py
@@ -0,0 +1,118 @@
+import re
+
+class Expression:
+
+    def __init__(self, val=None, gauche=None, droite=None):
+        if Token.isNumber(val) and (gauche != None or droite != None):
+            raise AttributeError("gauche et droite ne peuvent pas exister si val est un nombre")
+        self.val = val
+        self.gauche = gauche
+        self.droite = droite
+
+    def evalue(self):
+        if self.val == Token.OPERAND_ADDITION:
+            return self.gauche.evalue() + self.droite.evalue()
+        elif self.val == Token.OPERAND_MULTIPLICATION:
+            return self.gauche.evalue() * self.droite.evalue()
+        else:
+            return int(self.val)
+
+    def __str__(self):
+        if Token.isNumber(self.val):
+            return str(self.val)
+        return "(" + str(self.gauche.__str__()) + str(self.val) + str(self.droite.__str__()) + ")"
+
+
+class Token:
+    ADDITION = "+"
+    MULTIPLICATION = "*"
+    PARENTHESE_OUVERTE = "("
+    PARENTHESE_FERME = ")"
+
+    NUMBER = re.compile(r'\d+')
+
+    @staticmethod
+    def isNumber(n):
+        return Token.NUMBER.match(str(n)) is not None
+
+def tokenize(text):
+    buffer = ""
+    tokens = []
+    for char in text:
+        if Token.isNumber(char):
+            buffer += char
+            continue
+        elif char == " ":
+            continue
+
+        if buffer != "":
+            tokens.append(buffer)
+            buffer = ""
+        tokens.append(char)
+    return tokens
+
+def arbre(tokens): #-> Expression
+    print(tokens)
+    current = None
+    waiting_before_exp = None
+    waiting_for_after_exp = None
+
+    ##Brackets loop
+    i = 0
+    while i != len(tokens):
+        if tokens[i] == "(":
+            j = i + 1
+            innerBrackets = 1
+            innerTokens = []
+            while tokens[j] != ")" and innerBrackets != 0:
+                if tokens[j] == "(":
+                    innerBrackets += 1
+                elif tokens[j] == ")":
+                    innerBrackets -= 1
+                innerTokens.append(tokens[j])
+                j += 1
+            exp = arbre(innerTokens)
+            if waiting_for_after_exp != None:
+                waiting_for_after_exp.droite == exp
+            else:
+                waiting_before_exp = exp
+        elif tokens[i] == "*":
+            exp = Expression("*")
+            if Token.isNumber(tokens[i-1]):
+                exp.gauche == tokens[i-1]
+            if Token.isNumber(tokens[i+1]):
+                exp.droite == tokens[i+1]
+            if Token.isNumber(tokens[i-1]) and Token.isNumber(tokens[i+1]):
+                return exp
+
+            if tokens[i-1] == ")":
+                exp.gauche == waiting_before_exp
+                waiting_before_exp = None
+            elif tokens[i+1] == "(":
+                waiting_for_after_exp = exp
+            else:
+                raise Exception()
+            
+            
+        i += 1
+
+    ##Multiplication loop
+    #i = 0
+    #while i != len(tokens):
+    #    if tokens[i] == "*":
+    #        print("at")
+    #        return Expression("*", tokens[i-1], tokens[i+1])
+    #    i += 1
+    ##Addition loop
+    #i = 0
+    #while i != len(tokens):
+    #    if tokens[i] == "+":
+    #        return Expression("+", tokens[i-1], tokens[i+1])
+    #    i += 1
+
+    return waiting_for_after_exp
+
+
+
+if __name__ == "__main__":
+    print(arbre(tokenize("4*(7*4)")))
diff --git a/lexer.py b/lexer.py
deleted file mode 100644
index 34a8e71..0000000
--- a/lexer.py
+++ /dev/null
@@ -1,6 +0,0 @@
-import re
-
-class Token:
-    OPERAND_ADDITION = "+"
-    OPERAND_MULTIPLICATION = "*"
-    NUMBER = re.compile(r'\d+') #CHANGER