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@LarynQi
Last active Jul 14, 2020
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CS61A SU20 Discussion 06
import doctest
import sys
import argparse
"""
---USAGE---
python3 disc06.py <name_of_function>
e.g python3 disc06.py stepper
---NOTES---
- if you pass all the doctests, you will get no terminal output
- if you want to see the verbose output (all output shown even if the function is correct), run this:
python3 disc06.py <name_of_function> -v
- if you want to test all of your functions, run this:
python3 disc06.py all
"""
### Discussion 06 ###
#########
# Nonlocal
#########
# Q1.1
def stepper(num):
"""
>>> s = stepper(3)
>>> s()
_______
>>> s()
_______
"""
"*** ENVIRONMENT DIAGRAM ***"
def step():
nonlocal num
num = num + 1
return num
return step
# Q1.2
def memory_1(n):
"""
>>> f = memory_1(10)
>>> f(lambda x: x * 2)
20
>>> f(lambda x: x - 7)
13
>>> f(lambda x: x > 5)
True
"""
"*** UNCOMMENT SKELETON ***"
# def f(g):
# ________________________
# ________________________
# ________________________
# return f
#########
# Midterm Review
#########
# Q2.1
def sixty_one_a():
"""
>>> from operator import add
>>> six = 1
>>> def ty(one, a):
... summer = one(a, six)
... return summer
>>> six = ty(add, 6)
>>> summer = ty(add, 6)
"""
"*** ENVIRONMENT DIAGRAM ***"
pass
# Q2.2
def nonlocalist():
"""
>>> prepend, get = nonlocalist()
>>> prepend(2)
>>> prepend(3)
>>> prepend(4)
>>> get(0)
4
>>> get(1)
3
>>> get(2)
2
>>> prepend(8)
>>> get(2)
3
"""
"*** UNCOMMENT SKELETON ***"
# get = lambda x: "Index out of range!"
# def prepend(value):
# _______________________________________________________
# f = ___________________________________________________
# def get(i):
# if i == 0:
# return value
# return ___________________(_______________________)
# _______________________________________________________
# return _________________________, _________________________
# Q2.3
def list_comp():
"""
>>> f = ________________________________________________
>>> f = f(10)
1
2
3
4
5
6
7
8
9
10
>>> f
___________________
"""
pass
# Q2.4
square = lambda x: x * x
double = lambda x: 2 * x
def memory_2(x, f):
"""Return a higher-order function that prints its memories.
>>> f = memory_2(3, lambda x: x)
>>> f = f(square)
3
>>> f = f(double)
9
>>> f = f(print)
6
>>> f = f(square)
3
None
"""
"*** UNCOMMENT SKELETON ***"
# def g(h):
# print(________________________________________)
# return _______________________________________
# return g
# Q2.5
def announce_losses(who, last_score=0):
"""
>>> f = announce_losses(0)
>>> f1 = f(10, 0)
>>> f2 = f1(1, 10) # Player 0 loses points due to swine swap
Oh no! Player 0 just lost 9 point(s).
>>> f3 = f2(7, 10)
>>> f4 = f3(7, 11) # Should not announce when player 0's score does not change
>>> f5 = f4(11, 12)
"""
"*** UNCOMMENT SKELETON ***"
# assert who == 0 or who == 1, 'The who argument should indicate a player.'
# def say(score0, score1):
# if who == 0:
# score = ________________________
# elif who == 1:
# score = ________________________
# if ________________________:
# ________________________________________________
# return ________________________
# return say
# Q2.6
def fox_says(start, middle, end, num):
"""
>>> fox_says('wa', 'pa', 'pow', 3)
'wa-pa-pa-pa-pow'
>>> fox_says('fraka', 'kaka', 'kow', 4)
'fraka-kaka-kaka-kaka-kaka-kow'
"""
"*** UNCOMMENT SKELETON ***"
# def repeat(k):
# if ________________________:
# ________________________
# else:
# ________________________
# return start + '-' + repeat(num) + '-' + end
# Q2.7
def primary_stress(t):
"""
>>> word = tree("", [
... tree("w", [tree("s", [tree("min")]), tree("w", [tree("ne")])]),
... tree("s", [tree("s", [tree("so")]), tree("w", [tree("ta")])])])
>>> primary_stress(word)
'so'
>>> phrase = tree("", [
... tree("s", [tree("s", [tree("law")]), tree("w", [tree("degree")])]),
... tree("w", [tree("requirement")])])
>>> primary_stress(phrase)
'law'
"""
"*** UNCOMMENT SKELETON ***"
# def helper(t, num_s):
# if is_leaf(t):
# return [label(t), num_s]
# if label(t) == "s":
# num_s = ________________________
# return max([________________________________________________],
# key = ________________________)
# return ________________________
# Q2.8
def subset_sum(seq, k):
"""
>>> subset_sum([2, 4, 7, 3], 5) # 2 + 3 = 5
True
>>> subset_sum([1, 9, 5, 7, 3], 2)
False
>>> subset_sum([1, 1, 5, -1], 3)
False
>>> 3 in [1, 2, 3] # Note: You can use the in operator to determine if an element belongs to a list
True
>>> 4 in [1, 2, 3]
False
"""
"*** UNCOMMENT SKELETON ***"
# if ______________________________________________________________________________:
# return True
# elif ____________________________________________________________________________:
# return False
# else:
# return ______________________________________________________________________
# Tree ADT
# Constructor
def tree(label, branches=[]):
"""Construct a tree with the given label value and a list of branches."""
for branch in branches:
assert is_tree(branch)
return [label] + list(branches)
# Selector
def label(tree):
"""Return the label value of a tree."""
return tree[0]
# Selector
def branches(tree):
"""Return the list of branches of the given tree."""
return tree[1:]
def is_tree(tree):
"""Returns True if the given tree is a tree, and False otherwise."""
if type(tree) != list or len(tree) < 1:
return False
for branch in branches(tree):
if not is_tree(branch):
return False
return True
# For convenience
def is_leaf(tree):
"""Returns True if the given tree's list of branches is empty, and False
otherwise."""
return not branches(tree)
### For running tests only. Not part of discussion content ###
parser = argparse.ArgumentParser(description="Test your work")
parser.add_argument("func", metavar="function_to_test", help="Function to be tested")
parser.add_argument("-v", dest="v", action="store_const", const=True, default=False, help="Verbose output")
args = parser.parse_args()
try:
if args.func == "all":
if args.v:
doctest.testmod(verbose=True)
else:
doctest.testmod()
else:
if args.v:
doctest.run_docstring_examples(globals()[args.func], globals(), verbose=True, name=args.func)
else:
doctest.run_docstring_examples(globals()[args.func], globals(), name=args.func)
except:
sys.exit("Invalid Arguments")
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