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

# In[ ]:


from __future__ import print_function


# ### We will see more examples of functions and other things that you might have forgotten 

# #### You can have a list of lists
# 

# In[2]:


# e.g.
x=[1,2,3,4,5] 
#what is x[0]? Answer: 1
x=['a','b','c','d']
#what is x[0]? Answer: a
x=[[1,2],3,[4,5,6,7]]  
#what is x[0]? Answer: [1,2]
#what is x[1]? Answer: 3
#what is x[2]? Answer: [4,5,6,7]
#what is len(x)? Answer: [3]
#what is x[0][0]? Answer: 1
#what is x[0][1]? Answer: 2
#what is len(x[0][0])? Answer: error because 1 is an int
#what about len(x[0])? Answer: 2


# ### Assigning variables

# In[5]:


a=5
b=6

a=b #what is a? Answer=6
b=a #what is b? Answer=6
new_a=a #what is new_a? Answer=6
a=b #now what is a? Answer=6
b=new_a #now what is b? Answer=6


# ### What if you wanted to have a=6 and b=5? How would you do this?

# In[11]:


a=5
b=6
a,b=b,a
print('-----Method 1-----')
print(a)
print(b)
print('-----Method 2-----')
a=5
b=6
new_a=b
b=a
a=new_a
print(a)
print(b)


# In[13]:


#Defining a function

def myFunction(a): #a=5
    return 10*a

a=5
print(myFunction(a)) 
#What does this print?


# In[15]:


#Defining a function

def myFunction(a): #a=5
    print(10*a)

a=5
print(myFunction(a)) 
#What does this print?


# ##### Why does it print 50 and then None?

# In[16]:


#Defining a function

def myFunction(a): #a=5
    print(10*a)
    return a

a=5
print(myFunction(a)) 
#What does this print?


# ##### Why does it print 50 and then 5?

# In[17]:


#Defining a function

def myFunction(a): #a=5
    print(10*a)
    return a
    print ('My name is Timnit')

a=5
print(myFunction(a)) 
#What does this print?


# #### Nothing gets executed after the return function so we don't print _My name is Timnit_

# In[19]:


#Defining a function

def myFunction(a): #a=5
    print(10*a)
    return a
    print ('My name is Timnit')

a=5
z=myFunction(a)
print(z)
#What does this print?


# In[20]:


#Defining a function

def myFunction(a): #a=5
    print(10*a)
return a  #What is wrong here?
    print ('My name is Timnit') #What is wrong here?

a=5
z=myFunction(a)
print(z)
#What does this print?


# #### We cannot have a _return_ statement _outside_ of a function or we will get an error like below

# In[22]:


#Defining a function

def myFunction(a): #a=5
    print(10*a)
return a
print ('My name is Timnit')

a=5
z=myFunction(a)
print(z)
#What does this print?