diff --git a/parser/src/lexer.rs b/parser/src/lexer.rs
index fd2c6fc3a..25d9ca723 100644
--- a/parser/src/lexer.rs
+++ b/parser/src/lexer.rs
@@ -1,8 +1,8 @@
-use std::str::FromStr;
-use std::str::CharIndices;
 pub use super::token::Tok;
-use std::iter::FromIterator;
 use std::collections::HashMap;
+use std::iter::FromIterator;
+use std::str::CharIndices;
+use std::str::FromStr;
 
 pub struct Lexer<'input> {
     chars: CharIndices<'input>,
@@ -219,7 +219,6 @@ impl<'input> Lexer<'input> {
                         if col == l2 {
                             // TODO: handle wrong indentations
                         }
-
                     }
                 }
             }
@@ -270,9 +269,15 @@ impl<'input> Lexer<'input> {
                             match self.chr0 {
                                 Some('=') => {
                                     self.next_char();
-                                    return Some(Ok((tok_start, Tok::DoubleStarEqual, self.location + 1)));
-                                },
-                                _ => return Some(Ok((tok_start, Tok::DoubleStar, self.location + 1))),
+                                    return Some(Ok((
+                                        tok_start,
+                                        Tok::DoubleStarEqual,
+                                        self.location + 1,
+                                    )));
+                                }
+                                _ => {
+                                    return Some(Ok((tok_start, Tok::DoubleStar, self.location + 1)))
+                                }
                             }
                         }
                         _ => return Some(Ok((tok_start, Tok::Star, self.location + 1))),
@@ -382,7 +387,7 @@ impl<'input> Lexer<'input> {
                         Some('=') => {
                             self.next_char();
                             return Some(Ok((tok_start, Tok::NotEqual, self.location + 1)));
-                        },
+                        }
                         _ => panic!("Invalid token '!'"),
                     }
                 }
@@ -527,10 +532,14 @@ impl<'input> Iterator for Lexer<'input> {
         // let mut X = HashMap::new();
         // X.insert('=', Tok::Equal);
         let token = self.inner_next();
-        trace!("Lex token {:?}, nesting={:?}, indent stack: {:?}", token, self.nesting, self.indentation_stack);
+        trace!(
+            "Lex token {:?}, nesting={:?}, indent stack: {:?}",
+            token,
+            self.nesting,
+            self.indentation_stack
+        );
         token
     }
-
 }
 
 #[cfg(test)]
diff --git a/parser/src/lib.rs b/parser/src/lib.rs
index 2ace33281..614c80a1d 100644
--- a/parser/src/lib.rs
+++ b/parser/src/lib.rs
@@ -1,10 +1,10 @@
 #[macro_use]
 extern crate log;
 
+pub mod ast;
+mod lexer;
 pub mod parser;
 mod python;
-pub mod ast;
 mod token;
-mod lexer;
 
 pub use self::parser::parse;
diff --git a/parser/src/parser.rs b/parser/src/parser.rs
index 86e021dde..47da846ae 100644
--- a/parser/src/parser.rs
+++ b/parser/src/parser.rs
@@ -1,11 +1,11 @@
 use std::error::Error;
-use std::path::Path;
 use std::fs::File;
 use std::io::Read;
+use std::path::Path;
 
-use super::python;
 use super::ast;
 use super::lexer;
+use super::python;
 
 pub fn read_file(filename: &Path) -> Result<String, String> {
     match File::open(&filename) {
@@ -64,8 +64,8 @@ pub fn parse_expression(source: &String) -> Result<ast::Expression, String> {
 
 #[cfg(test)]
 mod tests {
-    use super::parse_program;
     use super::ast;
+    use super::parse_program;
 
     #[test]
     fn test_parse_print_hello() {
diff --git a/src/main.rs b/src/main.rs
index 6f0663ddd..634d2f74d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -58,12 +58,15 @@ fn run_script(script_file: &String) {
 }
 
 fn run_shell() {
-    println!("Welcome to the magnificent Rust Python {} interpreter", crate_version!());
+    println!(
+        "Welcome to the magnificent Rust Python {} interpreter",
+        crate_version!()
+    );
     let mut vm = VirtualMachine::new();
     // Read a single line:
     loop {
         let mut input = String::new();
-        print!(">>>>> ");  // Use 5 items. pypy has 4, cpython has 3.
+        print!(">>>>> "); // Use 5 items. pypy has 4, cpython has 3.
         io::stdout().flush().ok().expect("Could not flush stdout");
         io::stdin().read_line(&mut input);
         // input = input.trim().to_string();
diff --git a/vm/src/builtins.rs b/vm/src/builtins.rs
index b2378b2fb..904319443 100644
--- a/vm/src/builtins.rs
+++ b/vm/src/builtins.rs
@@ -1,7 +1,7 @@
 // use std::ops::Deref;
 use std::io::{self, Write};
 
-use super::pyobject::{PyObject, PyObjectKind, PyObjectRef, PyResult, PyContext, Executor};
+use super::pyobject::{Executor, PyContext, PyObject, PyObjectKind, PyObjectRef, PyResult};
 
 /*
  * Original impl:
@@ -76,22 +76,35 @@ pub fn len(args: Vec<Rc<NativeType>>) -> NativeType {
 
 pub fn make_module(ctx: &PyContext) -> PyObjectRef {
     // scope[String::from("print")] = print;
-    let obj = PyObject::new(PyObjectKind::Module { name: "__builtins__".to_string() }, ctx.type_type.clone());
-    obj.borrow_mut().dict.insert(
-        String::from("print"),
-        PyObject::new(PyObjectKind::RustFunction { function: print }, ctx.type_type.clone()),
-    );
-    obj.borrow_mut().dict.insert(
-        String::from("type"),
+    let obj = PyObject::new(
+        PyObjectKind::Module {
+            name: "__builtins__".to_string(),
+        },
         ctx.type_type.clone(),
     );
+    obj.borrow_mut().dict.insert(
+        String::from("print"),
+        PyObject::new(
+            PyObjectKind::RustFunction { function: print },
+            ctx.type_type.clone(),
+        ),
+    );
+    obj.borrow_mut()
+        .dict
+        .insert(String::from("type"), ctx.type_type.clone());
     obj.borrow_mut().dict.insert(
         String::from("all"),
-        PyObject::new(PyObjectKind::RustFunction { function: all }, ctx.type_type.clone()),
+        PyObject::new(
+            PyObjectKind::RustFunction { function: all },
+            ctx.type_type.clone(),
+        ),
     );
     obj.borrow_mut().dict.insert(
         String::from("any"),
-        PyObject::new(PyObjectKind::RustFunction { function: any }, ctx.type_type.clone()),
+        PyObject::new(
+            PyObjectKind::RustFunction { function: any },
+            ctx.type_type.clone(),
+        ),
     );
     obj
 }
diff --git a/vm/src/bytecode.rs b/vm/src/bytecode.rs
index b95521be5..3335df53a 100644
--- a/vm/src/bytecode.rs
+++ b/vm/src/bytecode.rs
@@ -121,7 +121,8 @@ pub enum BlockType {
 
 impl fmt::Debug for CodeObject {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let inst_str = self.instructions.iter()
+        let inst_str = self.instructions
+            .iter()
             .enumerate()
             .map(|(i, inst)| format!("Inst {}: {:?}", i, inst))
             .collect::<Vec<_>>()
diff --git a/vm/src/compile.rs b/vm/src/compile.rs
index 210a4078b..9466a9f22 100644
--- a/vm/src/compile.rs
+++ b/vm/src/compile.rs
@@ -16,33 +16,31 @@ pub fn compile(source: &String, mode: Mode) -> Result<CodeObject, String> {
     let mut compiler = Compiler::new();
     compiler.push_code_object(CodeObject::new());
     match mode {
-        Mode::Exec => {
-            match parser::parse_program(source) {
-                Ok(ast) => {
-                    compiler.compile_program(ast);
-                    Ok(compiler.pop_code_object())
-                }
-                Err(msg) => Err(msg),
+        Mode::Exec => match parser::parse_program(source) {
+            Ok(ast) => {
+                compiler.compile_program(ast);
+                Ok(compiler.pop_code_object())
             }
-        }
-        Mode::Eval => {
-            match parser::parse_statement(source) {
-                Ok(statement) => {
-                    let need_none = if let &ast::Statement::Expression { expression: _ } = &statement {
-                        false
-                    } else {
-                        true
-                    };
-                    compiler.compile_statement(statement);
-                    if need_none {
-                        compiler.emit(Instruction::LoadConst { value: bytecode::Constant::None });
-                    }
-                    compiler.emit(Instruction::ReturnValue);
-                    Ok(compiler.pop_code_object())
+            Err(msg) => Err(msg),
+        },
+        Mode::Eval => match parser::parse_statement(source) {
+            Ok(statement) => {
+                let need_none = if let &ast::Statement::Expression { expression: _ } = &statement {
+                    false
+                } else {
+                    true
+                };
+                compiler.compile_statement(statement);
+                if need_none {
+                    compiler.emit(Instruction::LoadConst {
+                        value: bytecode::Constant::None,
+                    });
                 }
-                Err(msg) => Err(msg),
+                compiler.emit(Instruction::ReturnValue);
+                Ok(compiler.pop_code_object())
             }
-        }
+            Err(msg) => Err(msg),
+        },
     }
 }
 
@@ -270,7 +268,7 @@ impl Compiler {
                     ast::Operator::BitXor => bytecode::BinaryOperator::Xor,
                     ast::Operator::BitAnd => bytecode::BinaryOperator::And,
                     ast::Operator::Subscript => bytecode::BinaryOperator::Subscript,
-                    ast::Operator::And | ast::Operator::Or => { panic!("Not possible") },
+                    ast::Operator::And | ast::Operator::Or => panic!("Not possible"),
                 };
                 self.emit(Instruction::BinaryOperation { op: i });
 
@@ -324,7 +322,9 @@ impl Compiler {
                     ast::Operator::BitXor => bytecode::BinaryOperator::Xor,
                     ast::Operator::BitAnd => bytecode::BinaryOperator::And,
                     ast::Operator::Subscript => bytecode::BinaryOperator::Subscript,
-                    ast::Operator::And | ast::Operator::Or => { panic!("Implement boolean short circuit?") },
+                    ast::Operator::And | ast::Operator::Or => {
+                        panic!("Implement boolean short circuit?")
+                    }
                 };
                 let i = Instruction::BinaryOperation { op: i };
                 self.emit(i);
diff --git a/vm/src/frame.rs b/vm/src/frame.rs
index 4e7a5fc6e..62bd83188 100644
--- a/vm/src/frame.rs
+++ b/vm/src/frame.rs
@@ -1,14 +1,14 @@
 use std::collections::HashMap;
-use std::rc::Rc;
 use std::fmt;
+use std::rc::Rc;
 
 use super::bytecode;
-use super::pyobject::{PyObject, PyObjectKind, PyObjectRef, PyResult, PyContext, Executor};
+use super::pyobject::{Executor, PyContext, PyObject, PyObjectKind, PyObjectRef, PyResult};
 
 #[derive(Clone, Debug)]
 pub struct Block {
     pub block_type: BlockType,
-    pub handler: usize,     // The destination we should jump to if the block finishes
+    pub handler: usize, // The destination we should jump to if the block finishes
                         // level?
 }
 
@@ -18,7 +18,7 @@ pub enum BlockType {
         start: bytecode::Label,
         end: bytecode::Label,
     },
-    B
+    B,
 }
 
 pub struct Frame {
@@ -29,7 +29,7 @@ pub struct Frame {
     blocks: Vec<Block>,      // Block frames, for controling loops and exceptions
     pub globals: HashMap<String, PyObjectRef>, // Variables
     pub locals: HashMap<String, PyObjectRef>, // Variables
-    pub lasti: usize,            // index of last instruction ran
+    pub lasti: usize,        // index of last instruction ran
                              // cmp_op: Vec<&'a Fn(NativeType, NativeType) -> bool>, // TODO: change compare to a function list
 }
 
@@ -97,22 +97,24 @@ impl Frame {
 impl fmt::Debug for Frame {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let stack_str = self.stack
-                    .iter()
-                    .map(|elem| format!("\n  > {}", elem.borrow_mut().str()))
-                    .collect::<Vec<_>>()
-                    .join("");
+            .iter()
+            .map(|elem| format!("\n  > {}", elem.borrow_mut().str()))
+            .collect::<Vec<_>>()
+            .join("");
         let block_str = self.blocks
-                    .iter()
-                    .map(|elem| format!("\n  > {:?}", elem))
-                    .collect::<Vec<_>>()
-                    .join("");
-        //
+            .iter()
+            .map(|elem| format!("\n  > {:?}", elem))
+            .collect::<Vec<_>>()
+            .join("");
         let local_str = self.locals
             .iter()
             .map(|elem| format!("\n  {} = {}", elem.0, elem.1.borrow_mut().str()))
             .collect::<Vec<_>>()
             .join("");
-        write!(f, "Frame Object {{ \n Stack:{}\n Blocks:{}\n Locals:{}\n}}", stack_str, block_str, local_str)
+        write!(
+            f,
+            "Frame Object {{ \n Stack:{}\n Blocks:{}\n Locals:{}\n}}",
+            stack_str, block_str, local_str
+        )
     }
 }
-
diff --git a/vm/src/lib.rs b/vm/src/lib.rs
index 53629aa98..d9ae932fd 100644
--- a/vm/src/lib.rs
+++ b/vm/src/lib.rs
@@ -9,11 +9,11 @@ mod builtins;
 pub mod bytecode;
 pub mod compile;
 pub mod eval;
+mod frame;
 mod objint;
 mod objstr;
 mod objtype;
 pub mod pyobject;
 mod vm;
-mod frame;
 
 pub use self::vm::VirtualMachine;
diff --git a/vm/src/objint.rs b/vm/src/objint.rs
index 1096acf80..8d4d2f819 100644
--- a/vm/src/objint.rs
+++ b/vm/src/objint.rs
@@ -1,4 +1,4 @@
-use super::pyobject::{PyObject, PyObjectKind, PyObjectRef, Executor};
+use super::pyobject::{Executor, PyObject, PyObjectKind, PyObjectRef};
 
 fn str(rt: &mut Executor, args: Vec<PyObjectRef>) -> Result<PyObjectRef, PyObjectRef> {
     Ok(rt.new_str("todo".to_string()))
@@ -13,10 +13,18 @@ fn set_attr(a: &mut PyObjectRef, name: String, b: PyObjectRef) {
 */
 
 pub fn create_type(type_type: PyObjectRef) -> PyObjectRef {
-    let typ = PyObject::new(PyObjectKind::Class { name: "int".to_string() }, type_type.clone());
+    let typ = PyObject::new(
+        PyObjectKind::Class {
+            name: "int".to_string(),
+        },
+        type_type.clone(),
+    );
     typ.borrow_mut().dict.insert(
         "__str__".to_string(),
-        PyObject::new(PyObjectKind::RustFunction { function: str }, type_type.clone()),
+        PyObject::new(
+            PyObjectKind::RustFunction { function: str },
+            type_type.clone(),
+        ),
     );
     typ
 }
diff --git a/vm/src/objstr.rs b/vm/src/objstr.rs
index 7bee4d604..09aea8285 100644
--- a/vm/src/objstr.rs
+++ b/vm/src/objstr.rs
@@ -1,4 +1,4 @@
-use super::pyobject::{PyObject, PyObjectKind, PyObjectRef, Executor, PyResult};
+use super::pyobject::{Executor, PyObject, PyObjectKind, PyObjectRef, PyResult};
 
 fn str_pos(s: &String, p: i32) -> usize {
     if p < 0 {
@@ -15,8 +15,8 @@ pub fn subscript(rt: &mut Executor, value: &String, b: PyObjectRef) -> PyResult
     match &(*b.borrow()).kind {
         &PyObjectKind::Integer { value: ref pos } => {
             let idx = str_pos(value, *pos);
-            Ok(rt.new_str(value[idx..idx+1].to_string()))
-        },
+            Ok(rt.new_str(value[idx..idx + 1].to_string()))
+        }
         &PyObjectKind::Slice {
             ref start,
             ref stop,
@@ -38,7 +38,7 @@ pub fn subscript(rt: &mut Executor, value: &String, b: PyObjectRef) -> PyResult
                 _ => unimplemented!(),
             };
             Ok(rt.new_str(value[start2..stop2].to_string()))
-        },
+        }
         _ => panic!(
             "TypeError: indexing type {:?} with index {:?} is not supported (yet?)",
             value, b
diff --git a/vm/src/objtype.rs b/vm/src/objtype.rs
index 084a5ada9..14a850923 100644
--- a/vm/src/objtype.rs
+++ b/vm/src/objtype.rs
@@ -9,9 +9,10 @@ use super::pyobject::{PyObject, PyObjectKind, PyObjectRef};
 
 pub fn create_type() -> PyObjectRef {
     let typ = PyObject::default().into_ref();
-    (*typ.borrow_mut()).kind = PyObjectKind::Class { name: "type".to_string() };
+    (*typ.borrow_mut()).kind = PyObjectKind::Class {
+        name: "type".to_string(),
+    };
     (*typ.borrow_mut()).typ = Some(typ.clone());
     // typ.borrow_mut().dict.insert("__str__".to_string(), PyObject::new(PyObjectKind::RustFunction { function: str }));
     typ
 }
-
diff --git a/vm/src/pyobject.rs b/vm/src/pyobject.rs
index 59fdb4b75..fc256e28b 100644
--- a/vm/src/pyobject.rs
+++ b/vm/src/pyobject.rs
@@ -1,11 +1,11 @@
-use std::rc::Rc;
-use std::fmt;
 use super::bytecode;
 use super::objint;
 use super::objtype;
 use std::cell::RefCell;
 use std::collections::HashMap;
+use std::fmt;
 use std::ops::{Add, Mul, Sub};
+use std::rc::Rc;
 
 /* Python objects and references.
 
@@ -147,9 +147,13 @@ pub enum PyObjectKind {
     Function {
         code: bytecode::CodeObject,
     },
-    Module { name: String },
+    Module {
+        name: String,
+    },
     None,
-    Class { name: String },
+    Class {
+        name: String,
+    },
     RustFunction {
         function: RustPyFunc,
     },
@@ -209,9 +213,14 @@ impl PyObject {
             PyObjectKind::Code { code: _ } => format!("<code>"),
             PyObjectKind::Function { code: _ } => format!("<func>"),
             PyObjectKind::RustFunction { function: _ } => format!("<rustfunc>"),
-            PyObjectKind::Module { ref name }=> format!("<module '{}'>", name),
-            PyObjectKind::Iterator { ref position, ref iterated_obj } => format!(
-                "<iter pos {} in {}>", position, iterated_obj.borrow_mut().str()
+            PyObjectKind::Module { ref name } => format!("<module '{}'>", name),
+            PyObjectKind::Iterator {
+                ref position,
+                ref iterated_obj,
+            } => format!(
+                "<iter pos {} in {}>",
+                position,
+                iterated_obj.borrow_mut().str()
             ),
             _ => {
                 println!("Not impl {:?}", self);
@@ -253,7 +262,6 @@ impl PyObject {
     pub fn into_ref(self) -> PyObjectRef {
         Rc::new(RefCell::new(self))
     }
-
 }
 
 impl<'a> Add<&'a PyObject> for &'a PyObject {
@@ -372,7 +380,7 @@ impl PartialEq for PyObject {
 
 #[cfg(test)]
 mod tests {
-    use super::{PyObjectKind, PyContext};
+    use super::{PyContext, PyObjectKind};
 
     #[test]
     fn test_add_py_integers() {
diff --git a/vm/src/vm.rs b/vm/src/vm.rs
index 1c13a6360..1bebfe220 100644
--- a/vm/src/vm.rs
+++ b/vm/src/vm.rs
@@ -6,19 +6,19 @@
 
 extern crate rustpython_parser;
 
+use std::cell::RefMut;
 use std::collections::HashMap;
+use std::ops::Deref;
 use std::path::Path;
 use std::rc::Rc;
-use std::cell::RefMut;
-use std::ops::Deref;
 
 use self::rustpython_parser::parser;
 use super::builtins;
 use super::bytecode;
 use super::compile;
-use super::pyobject::{PyObject, PyObjectKind, PyObjectRef, PyResult, PyContext, Executor};
+use super::frame::{Block, BlockType, Frame};
 use super::objstr;
-use super::frame::{Frame, Block, BlockType};
+use super::pyobject::{Executor, PyContext, PyObject, PyObjectKind, PyObjectRef, PyResult};
 
 // use objects::objects;
 
@@ -130,9 +130,12 @@ impl VirtualMachine {
             self.push_value(obj);
             None
         } else {
-            let name_error = PyObject::new(PyObjectKind::NameError {
-                name: name.to_string(),
-            }, self.get_type());
+            let name_error = PyObject::new(
+                PyObjectKind::NameError {
+                    name: name.to_string(),
+                },
+                self.get_type(),
+            );
             Some(Err(name_error))
         }
     }
@@ -232,9 +235,7 @@ impl VirtualMachine {
                 // TODO:
                 // self.invoke('__neg__'
                 match a.kind {
-                    PyObjectKind::Integer { value: ref value1 } => {
-                        Ok(self.ctx.new_int(-*value1))
-                    }
+                    PyObjectKind::Integer { value: ref value1 } => Ok(self.ctx.new_int(-*value1)),
                     _ => panic!("Not impl {:?}", a),
                 }
             }
@@ -244,7 +245,7 @@ impl VirtualMachine {
             Ok(value) => {
                 self.push_value(value);
                 None
-            },
+            }
             Err(value) => Some(Err(value)),
         }
     }
@@ -293,7 +294,7 @@ impl VirtualMachine {
             Ok(value) => {
                 self.push_value(value);
                 None
-            },
+            }
             Err(value) => Some(Err(value)),
         }
     }
@@ -312,10 +313,8 @@ impl VirtualMachine {
             PyObjectKind::Function { ref code } => {
                 let frame = Frame::new(Rc::new(code.clone()), HashMap::new(), None);
                 self.run_frame(frame).0
-            },
-            PyObjectKind::Class { name: _ } => {
-                self.new_instance(func_ref.clone(), args)
-            },
+            }
+            PyObjectKind::Class { name: _ } => self.new_instance(func_ref.clone(), args),
             _ => {
                 println!("Not impl {:?}", f);
                 panic!("Not impl");
@@ -336,7 +335,8 @@ impl VirtualMachine {
         match compile::compile(&source, compile::Mode::Exec) {
             Ok(bytecode) => {
                 debug!("Code object: {:?}", bytecode);
-                let obj = PyObject::new(PyObjectKind::Module { name: name.clone() }, self.get_type());
+                let obj =
+                    PyObject::new(PyObjectKind::Module { name: name.clone() }, self.get_type());
 
                 // As a sort of hack, create a frame and run code in it
                 let frame = Frame::new(Rc::new(bytecode), HashMap::new(), None);
@@ -390,9 +390,7 @@ impl VirtualMachine {
                 let obj = match value {
                     &bytecode::Constant::Integer { ref value } => self.ctx.new_int(*value),
                     // &bytecode::Constant::Float
-                    &bytecode::Constant::String { ref value } => {
-                        self.new_str(value.clone())
-                    }
+                    &bytecode::Constant::String { ref value } => self.new_str(value.clone()),
                     &bytecode::Constant::Code { ref code } => {
                         PyObject::new(PyObjectKind::Code { code: code.clone() }, self.get_type())
                     }
@@ -405,9 +403,7 @@ impl VirtualMachine {
                 self.import(name.to_string());
                 None
             }
-            &bytecode::Instruction::LoadName { ref name } => {
-                self.load_name(name)
-            }
+            &bytecode::Instruction::LoadName { ref name } => self.load_name(name),
             &bytecode::Instruction::StoreName { ref name } => {
                 // take top of stack and assign in scope:
                 self.store_name(name.clone())
@@ -419,13 +415,15 @@ impl VirtualMachine {
             }
             &bytecode::Instruction::BuildList { size } => {
                 let elements = self.pop_multiple(size);
-                let list_obj = PyObject::new(PyObjectKind::List { elements: elements }, self.get_type());
+                let list_obj =
+                    PyObject::new(PyObjectKind::List { elements: elements }, self.get_type());
                 self.push_value(list_obj);
                 None
             }
             &bytecode::Instruction::BuildTuple { size } => {
                 let elements = self.pop_multiple(size);
-                let list_obj = PyObject::new(PyObjectKind::Tuple { elements: elements }, self.get_type());
+                let list_obj =
+                    PyObject::new(PyObjectKind::Tuple { elements: elements }, self.get_type());
                 self.push_value(list_obj);
                 None
             }
@@ -457,42 +455,44 @@ impl VirtualMachine {
                 let stop = out[1];
                 let step = if out.len() == 3 { out[2] } else { None };
 
-                let obj = PyObject::new(PyObjectKind::Slice { start, stop, step }, self.ctx.type_type.clone());
+                let obj = PyObject::new(
+                    PyObjectKind::Slice { start, stop, step },
+                    self.ctx.type_type.clone(),
+                );
                 self.push_value(obj);
                 None
             }
-            &bytecode::Instruction::BinaryOperation { ref op } => {
-                self.execute_binop(op)
-            }
-            &bytecode::Instruction::LoadAttr { ref name } => {
-                self.load_attr(name.to_string())
-            }
-            &bytecode::Instruction::UnaryOperation { ref op } => {
-                self.execute_unop(op)
-            }
-            &bytecode::Instruction::CompareOperation { ref op } => {
-                self.execute_compare(op)
-            }
+            &bytecode::Instruction::BinaryOperation { ref op } => self.execute_binop(op),
+            &bytecode::Instruction::LoadAttr { ref name } => self.load_attr(name.to_string()),
+            &bytecode::Instruction::UnaryOperation { ref op } => self.execute_unop(op),
+            &bytecode::Instruction::CompareOperation { ref op } => self.execute_compare(op),
             &bytecode::Instruction::ReturnValue => {
                 let value = self.pop_value();
                 Some(Ok(value))
             }
             &bytecode::Instruction::PushBlock { start, end } => {
-                self.push_block(Block { block_type: BlockType::A { start, end }, handler: 0 });
+                self.push_block(Block {
+                    block_type: BlockType::A { start, end },
+                    handler: 0,
+                });
                 None
-            },
+            }
             &bytecode::Instruction::PopBlock => {
                 self.pop_block();
                 None
             }
             &bytecode::Instruction::GetIter => {
                 let iterated_obj = self.pop_value();
-                let iter_obj = PyObject::new(PyObjectKind::Iterator {
-                    position: 0, iterated_obj: iterated_obj
-                }, self.ctx.type_type.clone());
+                let iter_obj = PyObject::new(
+                    PyObjectKind::Iterator {
+                        position: 0,
+                        iterated_obj: iterated_obj,
+                    },
+                    self.ctx.type_type.clone(),
+                );
                 self.push_value(iter_obj);
                 None
-            },
+            }
             &bytecode::Instruction::ForIter => {
                 // The top of stack contains the iterator, lets push it forward:
                 let next_obj: Option<PyObjectRef> = {
@@ -500,7 +500,7 @@ impl VirtualMachine {
                     let mut ref_mut: RefMut<PyObject> = top_of_stack.deref().borrow_mut();
                     // We require a mutable pyobject here to update the iterator:
                     let mut iterator = ref_mut; // &mut PyObject = ref_mut.;
-                    // let () = iterator;
+                                                // let () = iterator;
                     iterator.nxt()
                 };
 
@@ -508,15 +508,26 @@ impl VirtualMachine {
                 match next_obj {
                     Some(value) => {
                         self.push_value(value);
-                    },
+                    }
                     None => {
+                        // Pop iterator from stack:
+                        self.pop_value();
+
                         // End of for loop
-                        let end_label = if let Block { block_type: BlockType::A { start, end }, handler } = self.last_block() { *end } else { panic!("Wrong block type") };
+                        let end_label = if let Block {
+                            block_type: BlockType::A { start, end },
+                            handler,
+                        } = self.last_block()
+                        {
+                            *end
+                        } else {
+                            panic!("Wrong block type")
+                        };
                         self.jump(end_label);
                     }
                 };
                 None
-            },
+            }
             &bytecode::Instruction::MakeFunction => {
                 let qualified_name = self.pop_value();
                 let code = self.pop_value();