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

# # Module 2
# 
# ## Video 6: Lists and List Operations
# **Python for the Energy Industry**
# 
# ## Lists
# 
# We often want to keep track of many bits of data at once. One way of doing this in python is with a 'list'. Lists are defined by enclosing multiple comma-separated values inside square brackets.

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# list of strings
vessels = ['ABIOLA', 'ACACIA']

# list of floats
prices = [1.23, 1.98, 1.45, 1.67]

# lists of integers
quantities1 = [18, 22, 21, 32]
quantities2 = [12, 11, 16, 18]


# ### Looping Over Lists

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# loop over prices
for price in prices:
    print(price)


# ### List Indexing
# 
# We can access individual items in a list in the following way:

# In[3]:


prices = [1.23, 1.98, 1.45, 1.67, 2.40, 1.89]

print('The 1st price: ', prices[0] )
print('The 2nd price: ', prices[1] )
print('The 3rd price: ', prices[2] )


# The number inside the square brackets is the 'index' of the item. Note that Python uses 'zero indexing', so the first item in a list has an index of 0.
# 
# You can also access items 'from the end' using a negative index. So an index of -1 gives the last item, -2 gives the second last item, and so on.

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print('The last price: ', prices[-1] )
print('The 2nd last price: ', prices[-2] )


# The index can also be used to overwrite an item in the list:

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print(prices)
prices[0] = 2.41
prices[-1] = 0.99
print(prices)


# You can also get a range of items from a list:

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print(prices[1:4] )


# This is called a 'slice'. Which indices from the prices list are included in this slice?  

# ## List Operations
# 
# Lists have some built in functionality that makes them easier to work with.
# 
# ### Adding to / Removing from Lists

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countries = ['USA', 'UK', 'France', 'Germany']

# adding on to the end of a list
countries.append('Spain')
print(countries)


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# inserting into a specific index of a list
countries.insert(2, 'Australia')
print(countries)


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# removing from a specific index
countries.pop(3)
print(countries)


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# removing a particular value from a list
countries.remove('Germany')
print(countries)


# ## Examining Lists

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primes = [2,3,5,7,11,13]

# check if a value is in a list
print(3 in primes)
print(4 in primes)


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# find the index of a value in a list
print(primes.index(5))


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# find the minimum, maximum, and sum
print('minimum:', min(primes))
print('maximum:', max(primes))
print('sum:', sum(primes))


# ### Other List Operations
# 
# The addition and multiplication operators also work on lists:

# In[14]:


print(quantities1 + quantities2)
print(quantities1 * 2)


# ### Exercise
# 
# Python allows you to have lists containing multiple different types of variable, as in the below example. Try to transform this list into: [1,2,3] using the operations you've learned.

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