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Python Workshop

Python Workshop

In Engineering College of Etawah , U.P. , India. I took a Python Beginner Workshop .
I used PPT of PyCon Texas for students

himanshu awasthi

May 09, 2018
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  1. A computer is a machine that stores pieces of information.

    A computer also moves, arranges, and controls that information (or data). A program is a detailed set of instructions that tells a computer what to do with that data.
  2. CodeSkulptor  Developed by Scott Rixner of Rice University to

    use for COMP 200.  Based on CodeMirror and Skulpt.  www.codeskulptor.org  If you want to learn more about using Python with CodeSkulptor after this class, check out the Coursera course “An Introduction to Interactive Programming in Python”! (9/15 – 11/16)  https://www.coursera.org/course/ interactivepython
  3. Recap: Explore! Makes changes, see how they impact the program

    as a whole. When in doubt, check the documentation. When super in doubt, Google it.
  4. Math Try typing this into CodeSkuptor: >>> print 3 +

    12 >>> print 12 - 3 >>> print 9 + 5 – 15 + 12 Operators: add: + subtract: - Note: don’t type the arrows >>> !
  5. Math Rule: If you want Python to answer in floats,

    you have to talk to it in floats. More operators: divide: / multiply: * >>> print 3 * 12 >>> print 12 / 3 >>> print 11 // 3 >>> print 12.0 / 3.0 >>> print 11.0 / 3.0 >>> print 11.0 // 3.0
  6. Math Comparison operators: == Equal to != Not equal to

    < Less than > Greater than <= Less than or equal to >= Greater than or equal to
  7. Math Practice: >>> print 2 < 3 True >>> print

    2 <= 2 False >>> print 3 > 2 True >>> print 2 != 3 True >>> print False < True True
  8. Strings Examples: Try typing one without quotes: What’s the result?

    >>> “It’s a beautiful day!” >>> “Goodbye, cruel world.” >>> Aggies >>> “Aggies” >>> “Rice fight, never die!” >>> “3 + 2”
  9. Strings String operators: concatenation: + multiplication: * Try concatenating: Try

    multiplying: >>> print “Hello” + “ “ + “world!” >>> print “HAHA” * 250
  10. Variables Calculate a value: How can you save that value?

    Give the value a name: >>> print 21 + 21 42 >>> ultimate_answer = 42 >>> ultimate_answer 42
  11. Variables Create a variable and give it a value: Now

    assign a new value: >>> headmaster = “Dumbledore” >>> print headmaster ‘Dumbledore’ >>> headmaster = “Hardcastle” >>> print headmaster ‘Hardcastle’ >>> color = “Brad Neely” >>> color = 12
  12. Variables  You can calculate a variable once, but keep

    the result to use later.  You can keep the same name for a variable, but change the value. Some other things that we can do with variables: Get an index from a string: Do some math: >>> headmaster = “Dumbledore” >>> print headmaster[2] >>> number = 3 >>> print headmaster[number - 2]
  13. Data Types We already know about three types of data:

    “Whoop!” string 42 integer 3.14159 float Python can tell us about types using the type() function: >>> print type(“Whoop!”) <type ‘str’> How would we get Python to output int and float types?
  14. Lists List: a sequence of objects >>> Beatles = [“John”,

    “Paul”, “George”, “Ringo”] >>> grades = [82, 93, 67, 99, 100] Guess what this will output: >>> type(Beatles) >>> type(grades)
  15. Lists List: a sequence of objects >>> Beatles = [“John”,

    “Paul”, “George”, “Ringo”] >>> grades = [82, 93, 67, 99, 100] Guess what this will output: >>> type(Beatles) <type ‘list’> >>> type(grades) <type ‘list’>
  16. Lists Index: Where an item is in the list >>>

    Beatles = [“John”, “Paul”, “George”, “Ringo”] >>> Beatles[0] ‘John‘ [“John”, “Paul”, “George”, “Ringo”] 0 1 2 3 Python always starts at zero!
  17. Booleans A boolean value can be: Is 1 equal to

    1? Is 15 less than 5? True or False. >>> print 1 == 1 True >>> print 15 < 5 False
  18. Booleans What happens when we type Boolean values in the

    interpreter? When the words ‘True’ and ‘False’ begin with upper case letters, Python knows to treat them like Booleans instead of strings or integers. >>> True >>> False >>> true >>> false >>> type(True) >>> type(“True”)
  19. Booleans and If both comparisons are True: If only one

    of the comparisons is True: If both of the comparisons are False: >>> 1==1 and 2==2 True >>> 1==1 and 2==3 False >>> 1==2 and 2==3 False
  20. Booleans or If both comparisons are True: If only one

    of the comparisons is True: If both of the comparisons are False: >>> 1==1 or 2==2 True >>> 1==1 or 2!=2 True >>> 1==2 or 2==3 False
  21. Booleans not You can use the word not to reverse

    the answer that Python gives: Any expression that is True can become False: >>> 1==1 True >>> not 1==1 False >>> not True False
  22. Booleans You can also use Booleans in their own expressions:

    >>> True and True >>> True and False >>> False and False >>> True or True >>> False or True >>> False or False >>> not True and True >>> not True or True
  23. if Statements Making decisions: If a condition is met, perform

    an action: “If you’re hungry, let’s eat lunch.” “If you like Frisbee, let’s play!” >>> state = “Texas” >>> if state == “Texas”: print “TX” TX
  24. if Statements Adding a choice: Adding a choice in our

    code with the else clause: “If you’re hungry, let’s eat lunch. Or else we can eat in an hour.” “If you like Frisbee, let’s play! Or else we can play rugby.” >>> if state == “Texas” print “TX” else: print “[inferior state]”
  25. if Statements Adding many choices: Adding more choices in our

    code with the elif clause: “If you like Frisbee, let’s play! Or else we can play rugby. Or else we can play Bioshock, or Half-Life, or Portal…” >>> if name == “Paige” print “Hi Paige!” elif name == “Walker”: print “Hi Walker!” else: print “Imposter!”
  26. Loops Loops are chunks of code that repeat a task

    over and over again.  Counting loops repeat a certain number of times.  Conditional loops keep going until a certain thing happens (or as long as some condition is True).
  27. Loops Counting loops repeat a certain number of times –

    they keep going until they get to the end of a count. >>> for mynum in [1, 2, 3, 4, 5]: print "Hello", mynum Hello 1 Hello 2 Hello 3 Hello 4 Hello 5 The for keyword is used to create this kind of loop, so it is usually just called a for loop.
  28. Loops Conditional loops repeat until something happens (or as long

    as some condition is True). >>> count = 0 >>> while (count < 4): print 'The count is:', count count = count + 1 The count is: 0 The count is: 1 The count is: 2 The count is: 3 The while keyword is used to create this kind of loop, so it is usually just called a while loop.
  29. How would I make a pot of coffee? 1. Get

    a flavor of ground coffee. 2. Get a coffee maker. 3. Get filter paper. 4. Get a pot of water. 5. Make sure the coffee maker is plugged in… …and on, and on, and on. But to us, it’s just “make a pot of coffee”.
  30. Remember how Algorithms are just instructions?  Functions are just

    a concise way to group instructions into a bundle. What it's like in our minds: “Make a pot of coffee.”  bundle In Python, you could say it like this: make_coffee(coffee_grounds, coffee_pot, water, filter_paper) ^ ^-----------------^---------------^-----------------^ function name function parameters
  31. Functions Let’s define a function in CodeSkulptor: >>> def beverage():

    print ‘Have you had a cup of coffee today?’ Now we’ll call the function: >>> beverage() Have you had a cup of coffee today?
  32. Functions But what if not everyone wants a cup of

    coffee? Let’s define a function with parameters: >>> def beverage(drink): print “Have you had a cup of ” + drink + “ today?’ Now we’ll call the function: >>> beverage(“Monster Zero”) Have you had a cup of Monster Zero today?
  33. Functions  Functions are defined using def.  Functions are

    called using parentheses ().  Functions take parameters and return outputs.  print displays information, but does not give a value.  return gives a value to the caller.