Initial commit

.gitignore

@@ -0,0 +1,4 @@
+.ipynb_checkpoints/
+.DS_Store
+*.pyc
+extras/

code/00_python_beginner_workshop.py

@@ -0,0 +1,81 @@
+'''
+Python Beginner Workshop
+'''
+
+'''
+Multi-line comments go between 3 quotation marks.
+You can use single or double quotes.
+'''
+
+# One-line comments are preceded by the pound symbol
+
+
+# BASIC DATA TYPES
+
+x = 5               # creates an object
+print type(x)       # check the type: int (not declared explicitly)
+type(x)             # automatically prints
+type(5)             # assigning it to a variable is not required
+
+type(5.0)           # float
+type('five')        # str
+type(True)          # bool
+
+
+# LISTS
+
+nums = [5, 5.0, 'five']     # multiple data types
+nums                        # print the list
+type(nums)                  # check the type: list
+len(nums)                   # check the length: 3
+nums[0]                     # print first element
+nums[0] = 6                 # replace a list element
+
+nums.append(7)              # list 'method' that modifies the list
+help(nums.append)           # help on this method
+help(nums)                  # help on a list object
+nums.remove('five')         # another list method
+
+sorted(nums)                # 'function' that does not modify the list
+nums                        # it was not affected
+nums = sorted(nums)         # overwrite the original list
+sorted(nums, reverse=True)  # optional argument
+
+
+# FUNCTIONS
+
+def give_me_five():         # function definition ends with colon
+    return 5                # indentation required for function body
+
+give_me_five()              # prints the return value (5)
+num = give_me_five()        # assigns return value to a variable, doesn't print it
+
+def calc(x, y, op):         # three parameters (without any defaults)
+    if op == 'add':         # conditional statement
+        return x + y
+    elif op == 'subtract':
+        return x - y
+    else:
+        print 'Valid operations: add, subtract'
+
+calc(5, 3, 'add')
+calc(5, 3, 'subtract')
+calc(5, 3, 'multiply')
+calc(5, 3)
+
+
+# EXERCISE: Write a function that takes two parameters (hours and rate), and
+# returns the total pay.
+
+def compute_pay(hours, rate):
+    return hours * rate
+
+compute_pay(40, 10.50)
+
+
+# FOR LOOPS
+
+# print each list element in uppercase
+fruits = ['apple', 'banana', 'cherry']
+for fruit in fruits:
+    print fruit.upper()

code/00_python_intermediate_workshop.py

@@ -0,0 +1,239 @@
+'''
+Python Intermediate Workshop
+'''
+
+'''
+LISTS
+'''
+
+# creating
+a = [1, 2, 3, 4, 5]     # create lists using brackets
+
+# slicing
+a[0]        # returns 1 (Python is zero indexed)
+a[1:3]      # returns [2, 3] (inclusive of first index but exclusive of second)
+a[-1]       # returns 5 (last element)
+
+# appending
+a[5] = 6        # error because you can't assign outside the existing range
+a.append(6)     # list method that appends 6 to the end
+a = a + [0]     # use plus sign to combine lists
+
+# checking length
+len(a)      # returns 7
+
+# checking type
+type(a)     # returns list
+type(a[0])  # returns int
+
+# sorting
+sorted(a)               # sorts the list
+sorted(a, reverse=True) # reverse=True is an 'optional argument'
+sorted(a, True)         # error because optional arguments must be named
+
+
+'''
+STRINGS
+'''
+
+# creating
+a = 'hello'     # can use single or double quotes
+
+# slicing
+a[0]        # returns 'h' (works like list slicing)
+a[1:3]      # returns 'el'
+a[-1]       # returns 'o'
+
+# concatenating
+a + ' there'        # use plus sign to combine strings
+5 + ' there'        # error because they are different types
+str(5) + ' there'   # cast 5 to a string in order for this to work
+
+# uppercasing
+a[0] = 'H'      # error because strings are immutable (can't overwrite characters)
+a.upper()       # string method (this method doesn't exist for lists)
+
+# checking length
+len(a)      # returns 5 (number of characters)
+
+
+'''
+EXERCISE:
+1. Create a list of the first names of your family members.
+2. Print the name of the last person in the list.
+3. Print the length of the name of the first person in the list.
+4. Change one of the names from their real name to their nickname.
+5. Append a new person to the list.
+6. Change the name of the new person to lowercase using the string method 'lower'.
+7. Sort the list in reverse alphabetical order.
+Bonus: Sort the list by the length of the names (shortest to longest).
+'''
+
+names = ['Wesley', 'Larry', 'Wan']  # list of names
+names[-1]                           # last element
+len(names[0])                       # length of first string
+names[0] = 'Wes'                    # overwrite existing element
+names.append('Gabriel')             # append new element
+names[-1] = names[-1].lower()       # change last string to be lowercase
+sorted(names, reverse=True)         # sort the list in reverse order
+sorted(names, key=len)              # sort the list by length
+
+
+'''
+FOR LOOPS AND LIST COMPREHENSIONS
+'''
+
+# for loop to print 1 through 5
+nums = range(1, 6)      # create a list of 1 through 5
+for num in nums:        # num 'becomes' each list element for one loop
+    print num
+
+# for loop to print 1, 3, 5
+other = [1, 3, 5]       # create a different list
+for x in other:         # name 'x' does not matter, not defined in advance
+    print x             # this loop only executes 3 times (not 5)
+
+# for loop to create a list of 2, 4, 6, 8, 10
+doubled = []                # create empty list to store results
+for num in nums:            # loop through nums (will execute 5 times)
+    doubled.append(num*2)   # append the double of the current value of num
+
+# equivalent list comprehension
+doubled = [num*2 for num in nums]   # expression (num*2) goes first, brackets
+                                    # indicate we are storing results in a list
+
+
+'''
+EXERCISE 1:
+Given that: letters = ['a', 'b', 'c']
+Write a list comprehension that returns: ['A', 'B', 'C']
+
+EXERCISE 2 (BONUS):
+Given that: word = 'abc'
+Write a list comprehension that returns: ['A', 'B', 'C']
+
+EXERCISE 3 (BONUS):
+Given that: fruits = ['Apple', 'Banana', 'Cherry']
+Write a list comprehension that returns: ['A', 'B', 'C']
+'''
+
+letters = ['a', 'b', 'c']
+[letter.upper() for letter in letters]  # iterate through a list of strings,
+                                        # and each string has an 'upper' method
+word = 'abc'
+[letter.upper() for letter in word]     # iterate through each character
+
+fruits = ['Apple', 'Banana', 'Cherry']
+[fruit[0] for fruit in fruits]          # slice the first character from each string
+
+
+'''
+DICTIONARIES
+'''
+
+# dictionaries are made of key-value pairs (like a real dictionary)
+family = {'dad':'Homer', 'mom':'Marge', 'size':2}
+
+# check the length
+len(family)         # returns 3 (number of key-value pairs)
+
+# use the key to look up a value (fast operation regardless of dictionary size)
+family['dad']       # returns 'Homer'
+
+# can't use a value to look up a key
+family['Homer']     # error
+
+# dictionaries are unordered
+family[0]           # error
+
+# add a new entry
+family['cat'] = 'snowball'
+
+# keys must be unique, so this edits an existing entry
+family['cat'] = 'snowball ii'
+
+# delete an entry
+del family['cat']
+
+# keys can be strings or numbers or tuples, values can be any type
+family['kids'] = ['bart', 'lisa']   # value can be a list
+
+# accessing a list element within a dictionary
+family['kids'][0]   # returns 'bart'
+
+# useful methods
+family.keys()       # returns list: ['dad', 'kids', 'mom', 'size']
+family.values()     # returns list: ['Homer', ['bart', 'lisa'], 'Marge', 2]
+family.items()      # returns list of tuples:
+                    # [('dad', 'Homer'), ('kids', ['bart', 'lisa']), ('mom', 'Marge'), ('size', 2)]
+
+
+'''
+EXERCISE:
+1. Print the name of the mom.
+2. Change the size to 5.
+3. Add 'Maggie' to the list of kids.
+4. Fix 'bart' and 'lisa' so that the first letter is capitalized.
+Bonus: Do this last step using a list comprehension.
+'''
+
+family['mom']                       # returns 'Marge'
+family['size'] = 5                  # replaces existing value for 'size'
+family['kids'].append('Maggie')     # access a list, then append 'Maggie' to it
+family['kids'][0] = 'Bart'          # capitalize names by overwriting them
+family['kids'][1] = 'Lisa'
+
+# or, capitalize using a list comprehension and the 'capitalize' string method
+family['kids'] = [kid.capitalize() for kid in family['kids']]
+
+# or, slice the string, uppercase the first letter, and concatenate with other letters
+family['kids'] = [kid[0].upper() + kid[1:] for kid in family['kids']]
+
+
+'''
+REQUESTS
+'''
+
+# import module (make its functions available)
+import requests
+
+# use requests to talk to the web
+r = requests.get('http://www.google.com')
+type(r)         # special 'response' object
+r.text          # HTML of web page stored as string
+type(r.text)    # string is encoded as unicode
+r.text[0]       # string can be sliced like any string
+
+
+'''
+APIs
+
+What is an API?
+- Application Programming Interface
+- Structured way to expose specific functionality and data access to users
+- Web APIs usually follow the "REST" standard
+
+How to interact with a REST API:
+- Make a "request" to a specific URL (an "endpoint"), and get the data back in a "response"
+- Most relevant request method for us is GET (other methods: POST, PUT, DELETE)
+- Response is often JSON format
+- Web console is sometimes available (allows you to explore an API)
+
+API Providers: https://apigee.com/providers
+Echo Nest API Console: https://apigee.com/console/echonest
+API key: http://bit.ly/myechonest
+'''
+
+# request data from the Echo Nest API
+r = requests.get('http://developer.echonest.com/api/v4/artist/top_hottt?api_key=KBGUPZPJZS9PHWNIN&format=json')
+r.text          # looks like a dictionary
+type(r.text)    # actually stored as a string
+r.json()        # decodes JSON
+type(r.json())  # JSON can be represented as a dictionary
+top = r.json()  # store that dictionary
+
+# store the artist data
+artists = top['response']['artists']    # list of 15 dictionaries
+
+# create a list of artist names only
+names = [artist['name'] for artist in artists]  # can iterate through list to access dictionaries