#!/usr/bin/env python
# coding: utf-8

# ![renumber-gif](http://i.imgur.com/ec6OXNR.gif)

# In[1]:


get_ipython().run_cell_magic('javascript', '', '\n$("#renumber-button").parent().remove();\n\nfunction renumber() {\n    // renumber cells in order, so it doesn\'t look like you made any mistakes\n    var i=1;\n    IPython.notebook.get_cells().map(function (cell) {\n        if (cell.cell_type == \'code\') {\n            // set the input prompt\n            cell.set_input_prompt(i);\n            // set the output prompt (in two places)\n            cell.output_area.outputs.map(function (output) {\n                if (output.output_type == \'execute_result\') {\n                    output.execution_count = i;\n                    cell.element.find(".output_prompt").text(\'Out[\' + i + \']:\');\n                }\n            });\n            i += 1;\n        }\n    });\n}\n\nIPython.toolbar.add_buttons_group([{\n  \'label\'   : \'Renumber\',\n  \'icon\'    : \'fa-list-ol\',\n  \'callback\': renumber,\n  \'id\'      : \'renumber-button\'\n}]);\n')


# In[2]:


time.time() - start


# In[3]:


time.time() - start


# In[4]:


import time
start = time.time()


# In[5]:


len(In)