1. Intro to CS Nov 13, 2017

2. Today’s Objectives
Strings

3. Strings >>> “Hello" # String with Double Quote ‘Hello'
>>> ‘world' # String with single Quote
‘world'
>>> msg1=‘Hello '
>>> msg2=“World!"
>>> msg = msg1 + msg2 # add 2 strings
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

4. Strings >>> msg2=“y'all" # This displays single quote
>>> msg = msg1 + msg2
>>> msg2='y"all'
>>> msg2=“y”all" # what does this print???
>>> msg2=“y\”all” # Add a double quote
>>> msg2=‘y\’all’ # Add a single quote
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

5. Strings >>> msg = msg1 * 3 + msg2 # Duplicate with *
>>> msg=‘Hel\nlo’ # Add a newline
>>> msg2=‘Hel\tlo’ # add a tab
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

6. Strings - extracting characters with []
>>> letters = 'abcdefghijklmnopqrstuvwxyz'
>>> letters[0]
'a'
>>> letters[1]
'b'
>>> letters[-1]
'z'
>>> letters[-2]
'y'
>>> letters[25]
>>> letters[5]
'f'
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

7. Strings - extracting characters with []
>>> letters = 'abcdefghijklmnopqrstuvwxyz'
>>> letters[0]
'a'
>>> letters[1]
'b'
>>> letters[-1]
'z'
>>> letters[-2]
'y'
>>> letters[25]
>>> letters[5]
'f'
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

8. Strings msg = msg1 * 3 + msg2 # Duplicate with *
msg1=‘Hel\nlo’ # Add a newline
msg2=‘Hel\tlo’ # add a tab
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

9. Strings len(<string>) - get length
letters = 'abcdefghijklmnopqrstuvwxyz'
len(letters)
empty=“”
len(empty)
<string>.split(<split_character>) - split a string using <split_character>
passed as parameter.
If no character, passed, defaults to SPACE
todos = 'get gloves,get mask,give cat vitamins,call ambulance'
todos.split(',')
todos.split()
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

10. Strings
String is a sequence of characters. Individual characters in a string can be accessed by [<index>]
fruit=‘banana’
fruit[0]
'b'
fruit[2]
'n'
fruit[5]
'a'
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

11. Strings - slice with [ start : end : step ]
mechanism to extract a substring (a part of a string) from a string
start - starting offset (character at this offset included)
end - end offset (characters unto one before this offset )
step - optional step size

12. • [ start :] specifies from the start offset to the end.
• [: end ] specifies from the beginning to the end offset minus 1.
• [ start : end ] indicates from the start offset to the end offset minus 1.
[ start : end : step ] extracts from the start offset to the end offset minus 1, skipping characters by step.
[:] extracts the entire sequence from start to end.

13. letters = 'abcdefghijklmnopqrstuvwxyz' letters[:]
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

14. letters = 'abcdefghijklmnopqrstuvwxyz'7

15. letters = 'abcdefghijklmnopqrstuvwxyz' letters[-6:-2] 'uvwx'
'ahov'
letters[4:20:3]
'ehknqt'
letters[19::4]
'tx'
TIMING 4 MINUTES (39 TOTAL)
ACTUAL – ran out of time
Now let’s take what we’ve learned and apply it to making a song
Here’s an example with the start of Mary had A Little Lamb
How can you execute a single program element? (double click)
Individual notes can be played by double clicking on them.
How can you execute a set of elements?
You can tell what will execute together by them sticking together
What white bar to know where you are inserting
pull the bottom off to differentiate from ‘move’
You can predict what will fit where by shape.
How do you delete an element?
How do you reorder elements
Notice the “Stop Script” block at the end. It’s always good programming practice to always have a “stop script” block and the end of any script so that you clearly indicate it’s the end.
In BYOB, you don’t necessarily need to have it there, but if you learn other language it will be very important to always make sure you clearly indicate the end of scripts 7

16. letters = 'abcdefghijklmnopqrstuvwxyz'
'afkpu'
letters[-1::-1]
'zyxwvutsrqponmlkjihgfedcba'
letters[::-1]