Problem Set 3 Solution

1.

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1
import random
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3
def fff():
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  screen=[]
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  for i in range(3):
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    line = []
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    for j in range(3):
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      if random.random() > 0.5:
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        line.append('#')
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      else:
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        line.append(' ')
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    screen.append(line)
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  for x in range(3):
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    for y in range(3):
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      print(screen[x][y], end='')
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    print()

2.

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7
1
def input_ratio(r):
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  def scale_factor(a):
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    return a,a*r,a*r**2,a*r**3,a*r**4
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  return scale_factor
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gs3=input_ratio(3)
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print(gs3(4))

3.

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1
def count_numbers(func):
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  def r_func(*args):
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    print('The numbers are: ')
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    func(*args)
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    count = str(len(args))
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    print('There are ' + count + ' numbers.')
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  return r_func
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@count_numbers
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def numbers(*args):
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  print(args)
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numbers(1,2,3,4)

4.

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1
class Food():
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    def __init__(self, name, price):
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        self.name = name
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        self.price = price
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    def get_info(self):
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        print(self.name + ' has a price of '+ str(self.price) + '.')
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    def update_price(self, new_price):
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        self.price = new_price
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class Fruit(Food):
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    def __init__(self, name, price, producing_area):
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        super().__init__(name, price)
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        self.producing_area = producing_area
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    def show_area(self):
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        print(self.name + ' is produced in ' + self.producing_area + '.')

5.

x
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class Num():
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    def __init__(self, num):
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        self.num=num
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    def sip(self,x):
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        if x in self.num:
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            for i in range(len(self.num)):
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                if self.num[i]==x:
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                    return i
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        else:
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            y = 0
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            for i in range(len(self.num)):
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                if self.num[i] < x:
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                    y = i + 1
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            return y

6.

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1
class Words():
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  def __init__(self, word):
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    self.word=word
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  def prefix(self):
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    length=100
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    for y in self.word:
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      if len(y)<=length:
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        length=len(y)
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        shortest=y
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    x_list=list(self.word)
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    x_list.remove(shortest)
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    for i in range(length):
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      for other in x_list:
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        if other[i]!=shortest[i]:
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          return shortest[:i]
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x=Words(("flower","flow","flight"))
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print(x.prefix())
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y=Words(("apple","application","appendix","appointment"))
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print(y.prefix())