# This is a comment line
# numbers and variables
age = 26
pi = 3.14159

# strings and methods
s = 'Hugh F Durrant-Whyte'

# Strings have a method `split` which returns a list of strings split by whitespace
tokens = s.split()
firstName = tokens[0]
middleName = tokens[1]
lastName = tokens[2]
s2 = firstName + ' ' + middleName + ' ' + lastName

# 'if' statement - indentation matters
if s == s2:
    print('yes the strings are equal')
else:
    print('no')

# if statements can also be inline
answer = 'yes' if s == s2 else 'no' 

# list (mutable ordered sequence)
beatles = ['John', 'Paul', 'George']
beatles.append('Ringo')
print(beatles)
print('Ringo' in beatles)


# 'for' loop - indentation matters
# Note that name is defined inside the for loop
for name in beatles:
    print('Hello ' + name)

# Iterating over a range of numbers is easy
# range has the following arguments (start, stop, step) where stop isn't included
for number in range(2, 10, 2):
    print(number)

# tuple (immutable ordered sequence)
ages = (18, 21, 28, 21, 22, 18, 19, 34, 9)

# Note you can't change the contents of a tuple

# set (mutable, unordered, no duplicates)
uniqueAges = set(ages)
uniqueAges.add(18) # already in set, no effect
uniqueAges.remove(21)


# testing set membership (very fast)
if 18 in uniqueAges:
    print('There is an 18-year-old present!')

# sorting a list
sorted(beatles) # returns a new sorted list
beatles.sort() # in-place - changes beatles list

# Sorting a set returns a list
orderedUniqueAges = sorted(uniqueAges)

# There is no guaranteed order when iterating over a set
for thisAge in uniqueAges:
    print(thisAge)

# Instead iterate over the sorted set:
for age in sorted(uniqueAges):
    print(age)

# dict - mapping unique keys to values
netWorth = {}
netWorth['Donald Trump'] = 3000000000
netWorth['Bill Gates'] = 58000000000
netWorth['Tom Cruise'] = 40000000
netWorth['Joe Postdoc'] = 20000

# Access the value associated with a key
print(netWorth['Donald Trump'])

# iterating over a dict gives keys
for personName in netWorth:
    print(personName + " is worth: ", end='')
    print(netWorth[personName])

# You can also iterate over key-value pairs:
for (person, worth) in netWorth.items():
    if worth < 1000000:
        print('haha ' + person + ' is not a millionaire')

# testing dict membership is the same as with a set
if 'Tom Cruise' in netWorth:
    print('show me the money!')