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

# # Advanced Lists
# 
# In this series of lectures we will be diving a little deeper into all the methods available in a list object. These aren't officially "advanced" features, just methods that you wouldn't typically encounter without some additional exploring. Its pretty likely that you've already encountered some of these yourself!
# 
# Lets begin!

# In[1]:


l = [1,2,3]


# ##append
# You will have definitely have use this method by now, which merely appends an element to the end of a list:

# In[2]:


l.append(4)

l


# ##count
# We discussed this during the methods lectures, but here it is again. count() takes in an element and returns the number of times it occures in your list:

# In[4]:


l.count(10)


# In[5]:


l.count(2)


# ##extend
# Many times people find the difference between extend and append to be unclear. So note:
# 
# **append: Appends object at end**

# In[6]:


x = [1, 2, 3]
x.append([4, 5])
print x


# **extend: extends list by appending elements from the iterable**

# In[7]:


x = [1, 2, 3]
x.extend([4, 5])
print x


# Note how extend append each element in that iterable. That is the key difference.

# ##index
# index will return the index of whatever element is placed as an argument. Note: If the the element is not in the list an error is returned.

# In[10]:


l.index(2)


# In[11]:


l.index(12)


# ##insert 
# insert takes in two arguments: insert(index,object) This method places the object at the index supplied. For example:

# In[12]:


l


# In[13]:


# Place a letter at the index 2
l.insert(2,'inserted')


# In[14]:


l


# ##pop
# You most likely have already seen pop(), which allows us to "pop" off the last element of a list. 

# In[15]:


ele = l.pop()


# In[16]:


l


# In[17]:


ele


# ##remove
# The remove() method removes the first occurrence of a value. For example:

# In[18]:


l


# In[19]:


l.remove('inserted')


# In[20]:


l


# In[21]:


l = [1,2,3,4,3]


# In[22]:


l.remove(3)


# In[23]:


l


# ##reverse
# As you might have guessed, reverse() reverses a list. Note this occurs in place! Meaning it effects your list permanently.

# In[24]:


l.reverse()


# In[25]:


l


# ##sort
# sort will sort your list in place:

# In[26]:


l


# In[27]:


l.sort()


# In[28]:


l


# **Great! You should now have an understanding of all the methods available for a list in Python!**