import

Announcements

• By next Monday 11:59 PM: "Project 1: Wordle"
  • By Tue: Display a word
  • By Wed: Check a guess
  • By Thr: Color letters
  • By Fri: Random word
  • By Sat: Change rows
  • By Sun: Color keys.
• Today and Tomorrow: Sections.

Announcements

• Our thinking is developing well but I think we are struggling with attention to do detail
• I will no longer be accepting:
  • Code that does not run
  • Questions related to indentation.
• You have now had a chance to submit 9 .py files for feedback (which I feel like I have done a pretty good job of providing?).
• Correct indentation will be necessary on the forthcoming midterm.
  • Basically: I am out of runway to grade leniently when code isn't correct.

Indentation

• These lines of code are different: def print_first_vowel(s:str): for c in s: if c in "aeiou": print(c) return def print_all_vowels(s:str): for c in s: if c in "aeiou": print(c) return

Indentation

• This code doesn't run, isn't commented, and it's not clear what it is intended to do. def vowel_print(s:str): for c in s: if c in "aeiou": print(c) return
• Ambigious name, no comments, ambigious code... No way to for me to fix this.

Indentation

• I am still seeing a bit of: for c in s: # line with a def, if, for, while ending with a : print(c) # line at the same indentation level
• This is never correct and was the subject of a week 1 lecture.
• My appeal:
  • As a rule, we are expected to place spaces in the correct places in our sentences.
  • A sar ule wear eexp ected top laces pace sin thec or rec tp lace sin our sent ences.

Projects

• As we advance to working on projects, after a series of (wildly successful) projects:
  • As a class, we now focus on "how to solve problems".
  • Typos are fine to make, but you should know how to solve the problem of typos.
  • Look back at e.g. the "debug" lecture for a systematic way.
• We want to discuss: "How can we combine 'for' and 'if' statements to solve this problem?"
• We don't want: "Should this line end with a colon?"

Today

• String patterns
• String formats
• Randomization
• Graphics

Methods to find string patterns

Method	Description
string.find(pattern)	Returns the first index of 'pattern' in 'string', or '-1' if it does not appear
string.find(pattern, k)	Same as the one-argument version, but starts searching at index 'k
string.rfind(pattern)	Returns the last index of 'pattern' is 'string', or '-1' if missing
string.rfind(pattern, k)	Same as the one-argument version, but searches backwards from index 'k
string.startswith(prefix)	Returns 'True' if the string starts with 'prefix
string.endswith(suffix)	Returns 'True' if the string ends with 'suffix

Some examples

• I never use these haha. >>> str = "hello world" >>> >>> str.rfind('o') 7 >>> str.rfind('lo') 3 >>> str.find('o') 4 >>> str.find('l') 2 >>> str.rfind('l') 9 >>> str.startswith("he") True >>> str.startswith("hl") False >>> str.endswith("lo") False >>> str.endswith("ld") True >>>

Random

• For Wordle, the game is only interesting if the secret word is not the same every time!
• Let’s take a moment to look at the built-inlibrary, which lets us simulate random processes
import random
• Like "import karel" basically, but with an important difference:
• We either must prefix with "random." >>> import random >>> random.random() # will be between 0 and 1 0.14444921034146263

Random

• We either must prefix with "random." >>> import random >>> random.random() # will be between 0 and 1 0.14444921034146263
• Or say "from random import *" >>> from random import * >>> random() # don't need prefix with 'from _ import *' >>> random() # don't need prefix with 'from _ import *' 0.1254407334152583

import random

random.randint(minv, maxv)	Returns an integer between minv and maxv, inclusive
random.randrange(limit)	Returns an integer from 0 up to but not including limit
random.randrange(start,limit)	Returns an integer from start up to but not including limit
random.random()	Returns a random float between 0 and 1
random.uniform(minv, maxv)	Returns a random float between minv and maxv
random.choice(str)	Returns a random character from the string
random.shuffle(str)	Randomly reorders the collection of characters

Random Examples

import random from english import * def random_five_letter_word(): random.shuffle(ENGLISH_WORDS) for word in ENGLISH_WORDS: if len(word) == 5: return word def random_no_repeated(): random.shuffle(ENGLISH_WORDS) for word in ENGLISH_WORDS: if not contains_repeated_letters(word): return word

The Portable Graphics Library

• In this class we use 'pgl.py' which is used in Wordle
• Just want to introduce it for now
• Can do: import pgl
• Operates on the idea of a collage or cork-board

• Newer objects can obscure older objects.

Blue Rectangle!

from pgl import *
gw = GWindow(500, 200) # like WordleGWindow
rect = GRect(150,50,0,0) #  answer = "blimp"
rect.set_color("Blue") # answer.upper()
rect.set_filled(True) 
gw.add(rect) # like word_to_row(answer)
from pgl import *
gw = GWindow(500, 200) # like WordleGWindow
rect = GRect(150,50,0,0) #  answer = "blimp"
rect.set_color("Blue") # answer.upper()
rect.set_filled(True) 
gw.add(rect) # like word_to_row(answer)
from pgl import *
gw = GWindow(500, 200) # like WordleGWindow
rect = GRect(150,50,0,0) #  answer = "blimp"
rect.set_color("Blue") # answer.upper()
rect.set_filled(True) 
gw.add(rect) # like word_to_row(answer)
from pgl import *
gw = GWindow(500, 200) # like WordleGWindow
rect = GRect(150,50,0,0) #  answer = "blimp"
rect.set_color("Blue") # answer.upper()
rect.set_filled(True) 
gw.add(rect) # like word_to_row(answer)
from pgl import *
gw = GWindow(500, 200) # like WordleGWindow
rect = GRect(150,50,0,0) #  answer = "blimp"
rect.set_color("Blue") # answer.upper()
rect.set_filled(True) 
gw.add(rect) # like word_to_row(answer)
from pgl import *
gw = GWindow(500, 200) # like WordleGWindow
rect = GRect(150,50,0,0) #  answer = "blimp"
rect.set_color("Blue") # answer.upper()
rect.set_filled(True) 
gw.add(rect) # like word_to_row(answer)

The Coordinate System

• Positions and distances on the screen are measured in terms of pixels
• Origin is in the upper left instead of lower left
• Vertical values increase as you move downwards

Other Simple Objects

Functions to create simple geometric objects:

• Rectangles/Squares + Circles/Ovals!
  • GRect( x, y, width, height )
  • GOval( x, y, width, height )
  • Creates a rectangle whose upper left corner is at (x,y) of the specified size
• Lines!
  • GLine( x1, y1, x2, y2 )
  • Creates a line extending from (x1,y1) to (x2,y2)

For Wordle

• Lower numbered rows are above higher numbered rows.
• Lower numbered columns are leftward of higher numbered columns.
  
  

  (0,0)	(0,1)	(0,2)	(0,3)	(0,4)
  (1,0)	(1,1)	(1,2)	(1,3)	(1,4)
  (2,0)	(2,1)	(2,2)	(2,3)	(2,4)
  (3,0)	(3,1)	(3,2)	(3,3)	(3,4)
  (4,0)	(4,1)	(4,2)	(4,3)	(4,4)
  (5,0)	(5,1)	(5,2)	(5,3)	(5,4)

• gw.set_square_letter(1, 3, '$') # example

  			$

Redact

• Suppose you want to take two strings, and one is secret (sh!)
• Examine them to see if they have the same letters at the same position, and
• "Redact" the letters that are the same in each word. def redact(word:str, secret:str) -> str: for i in range(len(word)): if word[i] == secret[i]: word = word[:i] + '*' + word[i+1:] DEBUG and print('Redact '+secret[i]+' at '+str(i)) return word

Announcements

• By next Monday 11:59 PM: "Project 1: Wordle"
  • By Tue: Display a word
  • By Wed: Check a guess
  • By Thr: Color letters
  • By Fri: Random word
  • By Sat: Change rows
  • By Sun: Color keys.