Introduction to Python Programming.pptx
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This document provides an introduction to Python programming and includes sample code and questions to test understanding of Python concepts. It covers topics like dictionaries, lists, recursion, functions, and vector addition. Four questions are included with explanations of sample code and solutions to correctly implement specified functions.
![Q.1. Are each of the following True or False
1.1 In Python the values of a dict must be immutable.
1.2 There exist problems that cannot be solved in Python without using either
iteration or recursion.
1.3 Floating point arithmetic behaves exactly like normal arithmetic on real
numbers.
1.4 On all inputs, a bisection search will run faster than a linear search.
1.5 Let L be a list, each element of which is a list of ints. In Python, the assignment
statement L[0][0] = 3 mutates the list L.
Solution:
1.1 FALSE. The values of keys must be immutable.
1.2 TRUE. Otherwise, the complexity of programs would be bound by the length of
the code.](https://image.slidesharecdn.com/introductiontopythonprogramming-230125083248-ffe21cd9/85/Introduction-to-Python-Programming-pptx-2-320.jpg)
![1.3 FALSE. Floating point provides only an approximation to real numbers.
1.4 FALSE. It has a higher asymptotic complexity, but there can be inputs on which
it will run more slowly. Consider, for example, searching for an element that
happens to the first element of the list.
1.5 FALSE, it mutates the list at L[0].
Q.2. What does the following code print?
T = (0.1, 0.1)
x = 0.0
for i in range(len(T)):
for j in T:
x += i + j
print x
print i
Solution:
0.1
0.2](https://image.slidesharecdn.com/introductiontopythonprogramming-230125083248-ffe21cd9/85/Introduction-to-Python-Programming-pptx-3-320.jpg)
![1.3
2.4
1
Q.3. What does the following code print?
def f(s):
if len(s) <= 1:
return s
return f(f(s[1:])) + s[0] #Note double recursion
print f('mat')
print f('math')
Solution:
atm
Hatm
Q.4. Implement the body of the function specified
def findAll(wordList, lStr):](https://image.slidesharecdn.com/introductiontopythonprogramming-230125083248-ffe21cd9/85/Introduction-to-Python-Programming-pptx-4-320.jpg)
!["""assumes: wordList is a list of words in lowercase.
lStr is a str of lowercase letters.
No letter occurs in lStr more than once
returns: a list of all the words in wordList that contain each of the letters in
lStr exactly once and no letters not in lStr.""“
Solution:
def findAll(wordList, letters):
result = []
letters = sorted(letters)
for w in wordList:
w = sorted(w)
if w == letters: result.append(w)
return result
Q.5. The following code does not meet its specification. Correct it.
def addVectors(v1, v2):
"""assumes v1 and v2 are lists of ints.
Returns a list containing the pointwise sum of the elements in v1 and v2.
For example](https://image.slidesharecdn.com/introductiontopythonprogramming-230125083248-ffe21cd9/85/Introduction-to-Python-Programming-pptx-5-320.jpg)
![addVectors([4,5], [1,2,3]) returns [5,7,3],and
addVectors([], []) returns []. Does not modify inputs."""
if len(v1) > len(v2):
result = v1
other = v2
else:
result = v2
other = v1
for i in range(len(other)):
result[i] += other[i]
return result
Solution:
insert the lines
v1 = v1[:]
v2 = v2[:]
before the first line of executable code.](https://image.slidesharecdn.com/introductiontopythonprogramming-230125083248-ffe21cd9/85/Introduction-to-Python-Programming-pptx-6-320.jpg)
Introduction to Python Programming.pptx
- 1. For any help regarding Python Homework Help visit : - https://www.pythonhomeworkhelp.com/, Email :- support@pythonhomeworkhelp.com or call us at :- +1 (315) 557-6473 Introduction To Python Programming
- 2. Q.1. Are each of the following True or False 1.1 In Python the values of a dict must be immutable. 1.2 There exist problems that cannot be solved in Python without using either iteration or recursion. 1.3 Floating point arithmetic behaves exactly like normal arithmetic on real numbers. 1.4 On all inputs, a bisection search will run faster than a linear search. 1.5 Let L be a list, each element of which is a list of ints. In Python, the assignment statement L[0][0] = 3 mutates the list L. Solution: 1.1 FALSE. The values of keys must be immutable. 1.2 TRUE. Otherwise, the complexity of programs would be bound by the length of the code.
- 3. 1.3 FALSE. Floating point provides only an approximation to real numbers. 1.4 FALSE. It has a higher asymptotic complexity, but there can be inputs on which it will run more slowly. Consider, for example, searching for an element that happens to the first element of the list. 1.5 FALSE, it mutates the list at L[0]. Q.2. What does the following code print? T = (0.1, 0.1) x = 0.0 for i in range(len(T)): for j in T: x += i + j print x print i Solution: 0.1 0.2
- 4. 1.3 2.4 1 Q.3. What does the following code print? def f(s): if len(s) <= 1: return s return f(f(s[1:])) + s[0] #Note double recursion print f('mat') print f('math') Solution: atm Hatm Q.4. Implement the body of the function specified def findAll(wordList, lStr):
- 5. """assumes: wordList is a list of words in lowercase. lStr is a str of lowercase letters. No letter occurs in lStr more than once returns: a list of all the words in wordList that contain each of the letters in lStr exactly once and no letters not in lStr.""“ Solution: def findAll(wordList, letters): result = [] letters = sorted(letters) for w in wordList: w = sorted(w) if w == letters: result.append(w) return result Q.5. The following code does not meet its specification. Correct it. def addVectors(v1, v2): """assumes v1 and v2 are lists of ints. Returns a list containing the pointwise sum of the elements in v1 and v2. For example
- 6. addVectors([4,5], [1,2,3]) returns [5,7,3],and addVectors([], []) returns []. Does not modify inputs.""" if len(v1) > len(v2): result = v1 other = v2 else: result = v2 other = v1 for i in range(len(other)): result[i] += other[i] return result Solution: insert the lines v1 = v1[:] v2 = v2[:] before the first line of executable code.