--- a/src/ast_dump.rs
+++ b/src/ast_dump.rs
@@ -5,8 +5,8 @@ use std::iter;
 impl boolop {
     fn to_string(&self) -> &'static str {
         match *self {
-            boolop::And => "and",
-            boolop::Or => "or"
+            boolop::And => " and ",
+            boolop::Or => " or "
         }
     }
 }
@@ -116,7 +116,13 @@ fn generators_to_string(generators: Vec<
 impl expr {
     fn to_string(&self) -> String {
         match self.clone() {
-            expr::BoolOp(op, values) => format!("{}({})", op.to_string(), args_to_string(values)),
+            expr::BoolOp(op, values) => {
+                let mut data = vec!();
+                for value in values {
+                    data.push(value.to_string());
+                }
+                data.join(op.to_string())
+            },
             expr::BinOp(a, op, b) => format!("{} {} {}", a.to_string(), op.to_string(), b.to_string()),
             expr::UnaryOp(op, operand) => format!("{}{}", op.to_string(), operand.to_string()),