image imagewidth (px) 1.7k 1.7k | id stringlengths 13 16 | text stringlengths 0 4.99k |
|---|---|---|
corpus-test-200 | 270 11 Classes
8. Suppose line 2 is changed to def init () :. What would room_1's attributes be initialized to?
a. length = 0, width = 0
b. length = 1, width = 1
C. Error
Instance attributes vs. class attributes
The attributes shown so far have been instance attributes. An instance attribute is a variable that is uniqu... | |
corpus-test-201 | 1.4 String basics 19
a. "wake" + "A"
b. "A +
wake"
C. "A" +
"wake"
10. A user enters "red" after the following line of code.
color = input ("What is your favorite color?")
Which produces the output "Your favorite color is red!"?
a. print ("Your favorite color is + color + !)
b. print ("Your favorite color is + "color" ... | |
corpus-test-202 | 271
| 11.2 Classes and instances |
| TRY IT |
| Creating a class for an airline's flight tickets |
| Write a class, FlightTicket, as described below. Default values follow the attributes. Then create a flight ticket and assign instance attribute with values from input. each read |
| Instance attributes: |
| flight_ num... | |
corpus-test-203 | 272 11 Classes
Instance attributes:
title:" "
author:"
year: 0
pages: 0
Class attribute:
imprint: Fantasy Tomes
Method:
init (): initializes the instance attributes
print_info (): prints book information (provided in template)
Given input:
Lord of the Bracelets
Blake R. R. Brown 1999
423
A Match of Thrones
Terry R. R. ... | |
corpus-test-204 | 11.3. Instance methods 273
CHECKPOINT
Creating patient vital signs instances
Access multimedia content http:///esssoooooooooooooooooooo
CONCEPTS IN PRACTICE
Defining and using _nit_ with parameters
Consider the example above.
1. Suppose the programmer wanted to make blood pressure a required parameter in _iii (). Which... | |
corpus-test-205 | 274 11 Classes
self.max_mph = max_mph
def max_kmh (self):
return self.max_mph * 1.609344
def update_max(self, speed) self.max_mph = speed
car_1 = ProductionCar((Mccaaenn 'Speedtail', 2020) # car_1.max_mph is 0.0 (rr_luppdatemaxx((2...2 # car_1.max_mph is 250.0
print(cca_1.make, sar_1.model, 'reaches', , tar_l.max_mphy ... | |
corpus-test-206 | 11.3. Instance methods 275
order
1. change (False, True)
4. What does order 1 represent at the end of the program?
a. 8 oz coffee
b. 8 oz coffee with milk
C. 8 oz coffee with sugar
5. Why is change () an instance method?
a. can change attributes
b. has multiple parameters
C. can change an instance
6. Can print_order be... | |
corpus-test-207 | 276 11 Classes
Refilled 100
Current
stock:
Access multimedia content http
Overloading operators
Learning objectives
By the end of this section you should be able to
Identify magic methods and describe their purpose.
Develop overloaded arithmetic and comparison operators for user-defined classes
Magic methods and custom... | |
corpus-test-208 | 11.4 Overloading operators 277
Overloading arithmetic operators
Operator overloading refers to customizing the function of a built-in operator. Arithmetic operators are commonly overloaded to allow for easy changes to instances of user-defined classes.
CHECKPOINT
Overloading _ad__( for a user-defined class, Account
Acc... | |
corpus-test-209 | 278 11 Classes
6. Which sub () definition overloads the operator for the code below to work?
class Pair:
def init (self, x=0, y=0)
self.x = X
self.y = y
# Define sub ()
p1 = Pair(10, 2)
p2 = Pair(8, 4)
p3 = p1 p2
print (p3.x, p3.y)
a. def sub (self):
return Pair(self.x other.x, self.y other.y)
b. def sub (self, other)
... | |
corpus-test-210 | 11.4 Overloading operators 279
11.4 Overloa
Overloading
| EXAMPLE 11.2 | | |
| | comparison operators for the Account class | |
| | Code | Output |
| | class Account: def init (self, name="", amount=0): self.name name self.amount amount = | |
| | def str_((slf)): | |
| | return f"{self.name}: [{self.amount)) ... | |
corpus-test-211 | 280 11 Classes
a. def le_ (other): :
return self.amount <= other.amount
b. def _e_ (self, other) : return self.amount <= other.amount
C. def le_ (self, other) return other.amount <= self.amount
9. Which type of value does gt () return?
a. account instance
b. Boolean
C. integer
TRY IT
Combining exercise logs
The Exercis... | |
corpus-test-212 | 20 1 Statements
Assigns the string "happy" to a variable, feel.
Prints the string "Hi Freda!" with a single print() function using the variable name.
Prints the string "I'm glad you feel happy. " with a single print () function using the variable feel.
Access multimedia content http://eesaaacciciii/ootorrrrooe
Number b... | |
corpus-test-213 | 11.5 Using modules with classes 281
int) returns True if my_var is an integer.
Expand the existing Account example so that the addition operator can also be used to add an integer value to an Account s amount attribute.
Access multimedia content httt:///ott...ooooorotooooooooot 1114ooeeroodiing-pprararrrs)
Using module... | |
corpus-test-214 | 282 11 Classes
Using aliases
Aliasing allows the programmer to use an alternative name for imported items. Ex: import triangle as tri allows the program to refer to the triangle module as tri. Aliasing is useful to avoid name collisions but should be used carefully to avoid confusion.
EXAMPLE 11.3
Using aliasing to imp... | |
corpus-test-215 | 11.6 Chapter summary 283
C. rogue_ level chhaaattrr game_char. . Level()
5. Which code creates a name collision?
a. character = 'Ranger'
b. Game_char = 'Ranger'
C. game_char = 'Ranger'
TRY IT
Missing import statement
Add the missing import statement to the top of the file. Do not make any changes to the rest of the cod... | |
corpus-test-216 | 284 11 Classes
| Construct | Description |
| Class definition | class ClassName: |
| | class ClassName: def init (self): # Initialize attributes |
| Attributes | class ClassName: class_attr_2 [value] = instance attr 2 [value] instance_attr_ [value] class_attr 1 [value] def __it_ (self): instance attr 1 [value] |
| Met... | |
corpus-test-217 | 11.6 Chapter summary 2
| Construct | Description |
| | class ClassName: # 0ther methods |
| Overloaded multiplication operator | def __mul_(selff other): return ClassName (welf. instance_attr ather.instance_attr22 |
| Import class from module with alias | from class_module import ClassName as ClassAlias |
Tahlo 11 Cha... | |
corpus-test-218 | 286 11 Classes
Access for free at openstax.org | |
corpus-test-219 | Recursion
Figure 12.1 credit: modification of work "Rings from the Ocean", by Sue Corbisez/Flicky CC BY 2.0
Chapter Outline
12.1 Recursion basics
12.2 Simple math recursion
12.3 Recursion with strings and lists
12.4 More math recursion
12.5 Using recursion to solve problems
12.6 Chapter summary
Introduction
Recursion i... | |
corpus-test-220 | 288 12 Recursion
CHECKPOINT
Three Towers
Access multimedia content http:///eeesoooooooooooooooooooo
CONCEPTS IN PRACTICE
Three Towers and recursion
1. How is the problem of moving two rings solved using recursion?
a. Move the small ring to the middle tower, move the bigger ring to the target tower, and move the small r... | |
corpus-test-221 | 12.2 Simple math recursion 289
5. How many total steps does it take to solve three rings?
a. 3
b. 4
C. 7
6. How many total steps does it take to solve four rings?
a. 15
b. 7
C. 3
Simple math recursion
Learning objectives
By the end of this section you should be able to
Identify a recursive case and a base case in a rec... | |
corpus-test-222 | 290 12 Recursion
3. Listing the primary numbers (prime numbers) greater than 3.
4. Listing the Fibonacci sequence of numbers.
Defining a recursive function
Recursive algorithms are written in Python as functions. In a recursive function different actions are performed according to the input parameter value. A critical ... | |
corpus-test-223 | OpenStax Rice University 6100 Main Street MS-375 Houston, Texas 77005
To learn more about OpenStax, visit https://openstax.org.
Individual print copies and bulk orders can be purchased through our website.
02024 Rice University. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution 4.0 ... | |
corpus-test-224 | 1.5 Number basics 21
What is the type of the following value?
"12.0"
a. string
b. int
C. float
Basic arithmetic
Arithmetic operators are used to perform mathematical operations like addition, subtraction, multiplication and division.
Four basic arithmetic operators exist in Python:
1. Addition (+)
2. Subtraction (-)
3.... | |
corpus-test-225 | 12.2 Simple math recursion 291
elif n 0: return n
return n else:
return n * rec_fact(n 1)
a. 355687428096000
b. 0
C. no result / infinite computation
7. def rec_fact(n): ifn < 0: print ("error") elif n == 0:
return 1 else:
return n * rec_fact(n 1)
a. 355687428096000
b. 0
c. no result infinite computation
8. def rec_fac... | |
corpus-test-226 | 292 12 Recursion
TRY IT
Write a program that computes the sum of the digits of a positive integer using recursion.
Ex: The sum of the digits of 6721 is 16.
Hint: There are 10 base cases, which can be checked easily with the right condition.
Access multimedia content hhtp://oooaaaa/////o/oooooooopmo 122-simpll-maahh-ecc... | |
corpus-test-227 | 12.3 Recursion with strings and lists 293
palindrome (word strip (word [0])).
a. Nothing. The function would work the same: the first and last letter would be removed.
b. Some words, such as "madamm", would be incorrectly recognized as a palindrome.
Recursion with lists
The animation below shows a recursive way to chec... | |
corpus-test-228 | 294 12 Recursion
a. True
b. False
8. list 1 = [1, 2, 3]
list _ = [1, 2, 3]
a. True
b. False
TRY IT
Remove duplicates
Write a recursive rem_dup() function that removes duplicates from a list.
Ex: List [5, 5, 2, 1, 3, 1, 6] should result in an output list [5, 2, 1, 3, 6].
Access multimedia content http://ghn.aaaaoooooooo... | |
corpus-test-229 | 12.4 More math recursion 295
Recursive
Fibonacci function
def fib(n)
# Base case if n == 0 or n == 1: return n # Recursive case elif n > 1:
return fib(n - 1) + fib - 2)
# Error case else:
print ("Fibonacci numbers begin at 0. ")
return
# &Test code
print (fib (7)
The above code's output is:
CHECKPOINT
Recursive Fibonac... | |
corpus-test-230 | 296 12 Recursion
a. tree
b. recursion tree
C. iteration tree
Greatest common divisor (GCD)
The greatest common divisor (GCD) of two positive integers is an integer that is a divisor for both integers. Ex: The GCD of 6 and 9 is 3 because 3 x 2 6, and 3 x
The GCD is found easily using Euclid's method. Euclid's method rec... | |
corpus-test-231 | 12.5 Using recursion to solve problems 297
5. How many recursive calls are made with gcd (24, 30)?
a. 4
b. 1
24
6. What is the GCD of 13 and 23?
a. 13
b. 1
C. 23
7. How many recursive calls are made with gcd (13, 23)?
a. 1
b. 8
C. 13
TRY IT
Write a recursive power () function, such that given an integer x and a positiv... | |
corpus-test-232 | 298 12 Recursion
Binary search
Searching a sorted list usually involves looking at each item. If the item being searched is not found, then the search can take a long time.
A binary search is a recursive algorithm used to efficiently search sorted lists. In each recursive step, about half the items are discarded as not... | |
corpus-test-233 | 12.5 Using recursion to solve problems 299
The above code's output is:
8
Not found
CHECKPOINT
Access multimedia content tttttst///ottoooooooooooooppoeeo
CONCEPTS IN PRACTICE
Binary search
1. Which list can be searched with the binary search algorithm?
a. [5, 2, 7, 1, 8]
b. [9, 8, 7, 6, 5]
C. [4, 5, 6, 7, 8]
2. If the b... | |
corpus-test-234 | 300 12 Recursion
EXAMPLE 12.4
Solving N towers
The solution to Three Towers is simple with recursion. In the code below, rings are numbered from the top down. The smallest ring is 1, the next ring is 2, and when solving for three rings, the bottom ring is 3.
Solving the towers problem recursively
def three_towers (N, s... | |
corpus-test-235 | 22 1 Statements
C. 2.5
2.9
6. What is the output of print (x / z)?
a. 3
b. 3.0
C. 3.5
7. What is the output of print(y / z)?
a. 0
b. 10
C. 10.0
8. What is the output of print (z * 1.5)?
a. 2
b. 3
C. 3.0
Operator precedence
When a calculation has multiple operators, each operator is evaluated in order of precedence. Ex:... | |
corpus-test-236 | 12.6 Chapter summary 301
CONCEPTS IN PRACTICE
Solving Three Towers
5. For four rings, how many total lines will be printed by three_towerd ()
a. 7
b. 15
6. Would an iterative solution to the Three Towers problem be more complex or less complex?
a. more complex
b. less complex
TRY IT
Coin combinations
Write a recursive ... | |
corpus-test-237 | 302
| 12 Recursion | |
| At this point, you | should be able to solve problems using recursion. |
| Function | Description |
| count (element) | Returns the number of times the element exists on the list on which the count () function called. is |
Table 12.1 Chapter 12 reference.
Access for free at openstax.org | |
corpus-test-238 | 13 Inheritance Figure 13.1 credit: modification of work "Don't stare...only sheep dogs stare...", by Bernard Spragg. NZ/Flickr, Public Domain Chapter Outline
13.1 Inheritance basics
13.2 Attribute access
13.3 Methods
13.4 Hierarchical inheritance
13.5 Multiple inheritance and mixin classes
13.6 Chapter summary
Introduc... | |
corpus-test-239 | 304 13 Inheritance
Is-a relationships can be confused with has-a relationships. A has-a relationship exists between a class that contains another class. Ex: An employee has a company-issued laptop. Note: The laptop is not an employee.
CHECKPOINT
is-a relationship between Employee and Developer
Access multimedia content... | |
corpus-test-240 | 13.1 Inheritance basics 305
CONCEPTS IN PRACTICE
Creating subclasses
4. How is a Daisy class that inherits from the Plant class defined?
a. class Plant (Daisy):
b. class Daisy (Plant):
C. class Daisy:
class Plant:
5. Suppose a CarryOn class is inherited from a Luggage class. How is a CarryOn instance created?
a. small_... | |
corpus-test-241 | | 306 | 13 Inheritance | | |
| | the class that inherits. This book uses superclass/subclass throughout for consistency. | | |
| | | Class inherited from | Class that inherits |
| | | superclass | subclass |
| | | base class | derived class |
| | | parent class | child class |
| | Table 13.1 | | |
| | ... | |
corpus-test-242 | 13.2 Attribute access 307
Creating a simple subclass
Subclasses have access to the attributes inherited from the superclass. When the subclass's _nit () isn't explicitly defined, the superclass's _inii__) method is called. Accessing both types of attributes uses the same syntax.
CHECKPOINT
Defining a simple subclass
Ac... | |
corpus-test-243 | 308 13 Inheritance
def bc_display(self)) :
class SubClass (SuperClass):
def ac_display(selff
print (fuSubclass: fself.feat_2?")
dc_1 = SubClass ( )
a. feat _
b. feat_l and feat_2
C. None
Using _ini__( to create and inherit instance attributes
A programmer often wants a subclass to have new instance attributes as well a... | |
corpus-test-244 | 13.2 Attribute access 309
self.hire_year = 2023
self.lang_xp = ["Python", "C++", "Java"]
def dev_display(self):
print (f"Proficient in {self. lang_xp}")
emp_1 Employee()
dev_1 1 = Developer()
4. What would be the output of dlv_1.dde_disppayy ()?
a. Employee 2 hired in 2023
b. Proficient in ['Python', 'C++', 'Java'
C. E... | |
corpus-test-245 | 310 13 Inheritance
Methods
Learning objectives
By the end of this section you should be able to
Write overridden methods to change behavior of inherited methods.
Use super () to access superclass methods.
Identify applications of polymorphism in method and function use.
Overriding methods
Sometimes a programmer wants t... | |
corpus-test-246 | 1.5 Number basics
| CONCEPTS IN PRACTICE |
| Multiple arithmetic operators |
| 9. What is the value of 4 * 3 ** 2 1? |
| a. 37 |
| b. 40 |
| C. 145 |
| 10. Which part of (1 + 3) ** 2 / 4 evaluates first? |
| b. 1 + 3 a. 4 ** 2 |
| C. 2 / 4 |
| 11. What is the value of -4 ** 2? |
| a. -16 |
| b. 16 |
| 12. How many oper... | |
corpus-test-247 | 13.3 Methods 311
b. ContractTaxDE's definition of calc_tax is missing a parameter.
C. ContractTaxDE can't override calc_tax() since ContractTax already has.
3. The following program doesn't override palc_tax( Why?
class Tax:
def (ilc_tax(self))
print ('Calculating tax')
total = 0 # To replace with calculation
return to... | |
corpus-test-248 | 312 13 Inheritance
6
def _init (self, ln=1, wd=1):
7
super() Umitt_(4
8
self.length = 1n
9
self.width = wd
10
11
class Square(Rectangle):
12
def _init_ (self, side=1):
13
super() cumit_(side,, side)
14
self.side = side
15
16
sq1 = Square(5)
17
4. Line 16 executes and Square's_intii () is called on line 12. Line 13 exec... | |
corpus-test-249 | 13.3 Methods 313
class Plant:
def Risplay(selff print ("I'm a plant")
class Mint (Plant):
def display (self): print ("I'm a mint")
class Lavender (Mint) :
def display (self): :
print ("I'm a lavender")
mint_1 = Mint()
Lavender_1 = Lavender()
lavender_ (1iddllayy
The code's output is:
I'm a mint
I'm a lavende
Polymorphi... | |
corpus-test-250 | 314 13 Inheritance
class ContractTax:
def _nnn (self, value):
self.value = value
def calc_tax(self):
print ("Calculating contracts tax")
total = 0.15 * self.value
# To replace with calculation
return total
my_tax = Contracttax(value=100)
# Replace 1000 with any value
result = my_tax.calc_tax()
print (f"Total tax: $fres... | |
corpus-test-251 | 13.3 Methods 315
CONCEPTS IN PRACTICE
Polymorphism in practice
8. Consider the example. What is the output?
class Polygon:
def print_type(self) print ("Polygon type")
class Rectangle (Polygon) def print_type(selff
print ("Rectangle type")
class Square (Rectangle) def print_type(self) print ("Square type")
sq_l Square()... | |
corpus-test-252 | 316 13 Inheritance
TRY IT
Using super(
Given the Employee class, create a Developer class inherited from Employee with methods __ntt___ () and print_info() such that:
Uses super () to call Employee's init () to initialize e_id and hire_year.
Assigns lang_xp with list parameter Lang_xp.
print_info()
Uses super() to prin... | |
corpus-test-253 | 13.4 Hierarchical inheritance 317
Class C inherits from Class D
2. Which group of classes is hierarchical inheritance appropriate for?
a. Cat, Dog, Bird
b. Employee, Developer, SalesRep
C. Dessert, BakedGood, ApplePie
Implementing hierarchical inheritance
Multiple classes can inherit from a single class by simply inclu... | |
corpus-test-254 | 318 13 Inheritance
mem_13 = Tenor()
mem_15 = Sopranol()
mem_10.display ()
print()
mem_13.display ()
print()
mem_15.display ()
The code's output is:
Current choir member
Part: Alto
Current choir member
Part: Tenor
Current choir member
Part: Soprano
Division: Soprano 1
CONCEPTS IN PRACTICE
Implementing hierarchical inher... | |
corpus-test-255 | 13.4 . Hierarchical inheritance 319
super (). init (a_attr, b_attr)
self d attr = d attr
b inst = (((2)
c inst = e(c_attr-
d inst D.D(6, 7)
3. What is the value of b_inst.b_attr?
a. 0
b. 2
C. Error
4. Which attributes does c_inst have access to?
a. a_attr
b. a_attr,c_attr
C. c_attr
5. Which attributes does d_inst have ... | |
corpus-test-256 | 320 13 Inheritance
Multiple inheritance and mixin classes
Learning objectives
By the end of this section you should be able to
Construct a class that inherits from multiple superclasses.
Identify the diamond problem within multiple inheritance
Construct a mixin class to add functionality to a subclass.
Multiple inherit... | |
corpus-test-257 | 24 1 Statements
4. Prints the content of variable feet in the output.
Access multimedia content http:/p//ooooooborrrrrrroppootee
1-5-number-basics)
Error messages
Learning objectives
By the end of this section you should be able to
Identify the error type and line number in error messages.
Correct syntax errors, name e... | |
corpus-test-258 | 13.5 Multiple inheritance and mixin classes 321
C. Error
2. What is the value of c_inst.c_attr?
a. 2
b. 20
C. Error
3. What is the value ofbiinst.a_attr?
a. 2
b. 4
C. Error
Figure 13.2 The diamond problem. If both Dessert and BakedGood override Food method, the overridden Food method that ApplePie inherits is ambiguous... | |
corpus-test-259 | 322 13 Inheritance
class Plant:
def psefosynth(self):
print (PPhooosynthesiziigg)
def eat(self):
class Rose(Plant):
pass
class Pitcher(Plant): pass
class VenusFlyTrap (Plant): pass
4. Which edit is appropriate?
a. Move eat () to a different class.
b. Remove Plant as a superclass.
5. The programmer edits the code as fol... | |
corpus-test-260 | 13.6 Chapter summary 323
class X:
def eat(self): :
print ("Eating")
class Rose (Plant): : pass
class Pitcher(Plants X)
pass
class SinusFlyTrap(Pland X) pass
a. CarnivClass
b. CarnivMixin
TRY IT
Fixing the diamond problem with a mixin class
The program below represents multiple inheritance and has the diamond problem. E... | |
corpus-test-261 | 324 13 Inheritance
Polymorphism describes a single representation for multiple forms and is applied in Python to define multiple methods with the same name and allow the same method to take different arguments.
Hierarchical inheritance is a type of inheritance in which multiple classes inherit from a single superclass.... | |
corpus-test-262 | 13.6 Chapter summary
| Task | Example |
| | class SuperClass: Sriint('Superclas method') def display(self): |
| Implement hierarchical inheritance | class SubClass1(SuperClasss: def display(self) Brint('Subclass 1 method )) class SubClass2(SuperClass) def display(self):: (aint((Suuclan 2 method') |
| | class SubClass... | |
corpus-test-263 | 326 13 Inheritance
Access for free at openstax.org | |
corpus-test-264 | File Edit Selection View New Text File Go Run Terminal Window Help New File... New Window Open... tery-rrc scripts Open Folder... Open Workspace from File... Open Recent 14 Files Figure 14.1 credit: Larissa Chu, CC BY 4.0 Chapter Outline
14.1 Reading from files
14.2 Writing to files
14.3 Files in different locations an... | |
corpus-test-265 | 328 14 Files
CHECKPOINT
Opening a file
Access multimedia content http:///eeaaoooooooooooooooooooo 14-1-readinggfrommffiee))
CONCEPTS IN PRACTICE
1. What is the correct way to open a file named firstfile.txt so that the file's contents can be read into a Python program?
a. open ("firstfile")
b. open ("firstfile.xx"))
C.... | |
corpus-test-266 | 14.1 Reading from files 329
55
5
91
*""Demonstrating read() and readlines()" """
# Using read()
# Open the file and associate with a file object
infile = open("input.txt")
# Read the contents of the file into a string str1 infile.read()
# Print str1 (rinult of using read():") (strt(strl)
# Always close the file once do... | |
corpus-test-267 | 330 14 Files
CHECKPOINT
read() and readline()
Access multimedia content http:///eessoooooooooooooooeetoa 14-1-reading-from-flless)
CONCEPTS IN PRACTICE
Reading files
Suppose fileobj = open ("input.txt") has already been executed for each question below.
input.txt:
Hello world!
How are you?
4. What is the correct way to... | |
corpus-test-268 | 1.6 Error messages 25
CONCEPTS IN PRACTICE
Parts of an error
Parts or an error
an
Given the following error message:
Traceback (most recent call last):
File f/hone/stttutttttee/////o//aap// line 2
print "test"
SyntaxError: Missing parentheses in call to 'print' Did you mean "rint("test")
1. What is the filename of the ... | |
corpus-test-269 | 14.2 Writing to files 331
TRY IT
Reading from a file line by line
file input.txt is shown. The file represents a set of integers. Line 1 of the file specifies how many integers follow. Write a program that reads from this file and determines the average of the numbers following the first line.
input.tx txt
Access multi... | |
corpus-test-270 | 332
| 14 Files | | |
| Parameter | Mode name and description | Example |
| | | fileobj |
| | Read mode: Open the specified file for reading. If the file does not exist, an error occurs. When no mode parameter is used, the default is to open a file in read mode. | open ("input. txt") same as: fileobj = open ("input... | |
corpus-test-271 | 14.2 Writing to files 333
The write () function writes automatically to a temporary store called the file buffer. To ensure that the information is written to a file, the close () function must be used. The close () function finalizes changes and closes the file.
EXAMPLE 14.2
Writing and appending to a file
"""Operatio... | |
corpus-test-272 | 334 14 Files
Read the original file:
Writing to a new file.
Second line.
Read the modified file:
Writing to a new file.
Second line.
Adding to the file.
Adding another line.
CHECKPOINT
write( and close
Access multimedia content tttp://oot....ooooooooooooooooee
CONCEPTS IN PRACTICE
Writing to files
resources.txt already... | |
corpus-test-273 | 14.3 Files in different locations and working with CSV files 335
b. The line "new content" is added to the end of resources.
TRY IT
Writing to a new file
Write a line of text to a file called out.txt. Don't forget to use close (). out.txt should only have the line of text that you have written.
Access multimedia conten... | |
corpus-test-274 | 14 Files
| Operating System | File location | open () function example |
| Mac | /users/student/ | fileobj open ("/users/sttudnn//uuupppttttt = |
| Linux | /usr/code/ | fileobj open ("/us//codeootpputtttxx)) |
| Windows | X:Aprojects) code\ | fileobj = open ("c://projeeesss/cccoouutptttttp or fileobj open Wpco\erroject... | |
corpus-test-275 | 14.3. Files in different locations and working with CSV files 337
such as text files (.txt), Python code files (.py), and other code files (.c,java).
Comma separated value (CSV, .CSV) files are often used for storing tabular data. These files store cells of information as Unicode separated by commas. CSV files can be r... | |
corpus-test-276 | 338 Files 14
# Remove \n character
row = row.strip ("\n")
# Spllit using commas
cells = row.split(",
# Print result print (list_csv)
The code's output is:
[[ Title,, Author' Pages'l, [ 11984'' George Orwell', 268 1, [ 'Jane
Eyre', Charlotte Bronte 532',, [ ('Walden' Henry David Thoreau', 156 ,,
['Moby Dick', Herman Mel... | |
corpus-test-277 | 14.4 Handling exceptions 339
EXPLORING FURTHER
Files such as Word documents (.docx) and PDF documents (.pdf), image formats such as Portable Network Graphics (PNG, .png) and Joint Photographic Experts Group (JPEG, .ppe or .jpg as well as many other file types are encoded differently.
Some types of non-Unicode files can... | |
corpus-test-278 | 340 14 Files
EXAMPLE 14.4
Typo in a file
A file named food_ordertxt has the following contents:
5 sandwiches
4 chips
1 pickle
soft drinks
The following program expects each line of the file to begin with an integer:
for line in open "'food_order.txtee
space = lineeindex(" ")
qty = int (line[:
item = Line[space+1:-1>
pr... | |
corpus-test-279 | 26
| Statements | | |
| Mistake | Error message | Explanation |
| prints ("You typed:", word) | NameError: name 'prints' is not defined | The spelling of print is incorrect. The accidentally programmer typed an extra letter. |
| print ("Hello") | IndentationError: unexpected indent | The programmer accidentally typed... | |
corpus-test-280 | 14.4 Handling exceptions 341
3. parts = line split()
qty = parts[0]
item = parts[1]
a. FileNotFoundErron
b. IndexError
C. ValueError
EXPLORING FURTHER
The Built-in Exceptions (htpp://pnnstxoogrr//Oxxxcxxpte page of the Python Standard Library explains the meaning of each exception.
Try and except
Programs can be design... | |
corpus-test-281 | 342 14 Files
Enter a filename: try_open. txt
File not found: try_open. txt
Have a nice day!
CONCEPTS IN PRACTICE
Predicting output with exceptions
For each code snippet, what is the output?
4. word = "one" try:
number = (nt(word)
print (word, "equals", number)
except ValueError:
print (word, "is not a number")
a. one e... | |
corpus-test-282 | 14.4 Handling exceptions 343
TRY IT
Type analyzer
Analysis programs often need to find numbers in large bodies of text. How can a program tell if a string like "123.45" represents a number? One approach is to use exceptions:
1. Try converting the string to an integer. If no ValueError is raised, then the string represe... | |
corpus-test-283 | 344 14 Files
httpss//ppenttxx.rrrrrrOococcte from Worldometer. Each line of the file includes a country's name, population, land area, and population density, separated by commas.
The user might incorrectly type the filename (Ex: countries.txt instead of countries.csv). Your program should output an error message if th... | |
corpus-test-284 | | | 14.5 Raising exceptions |
| 2 3 | SIZES { |
| 4 | "S" : ("Small", 5.99), |
| 5 | "M": ("Medium", , 7.99), |
| 6 | "L": ("Large", 9.99), |
| 7 8 | "XL": ("X-Large", 11.99), } |
| 9 | |
| 10 | def init (self, size): |
| 11 | if size not in Sizza.SIZES. |
| 12 | raise ValueBrror(E"Unkkomm size '{size}!") |
| 13 | se... | |
corpus-test-285 | 346 14 Files
C. TypeError: missing argument
2. raise "eizzError("Innaaa size")
a. Invalid size
b. PizzaError: Invalid size
C. NameError: name 'PizzaError' is not defined
3. raise ValueError
a. ValueError
b. NameError: name 'ValueError' is not defined
C. SyntaxError: Missing parenthesis in call to 'ValueError'
TRY IT
Th... | |
corpus-test-286 | 14.6 Chapter summary 347
Given the books.csv file, the output should be:
Found: ('Pride and Prejudice', 9780141439518)
Found: ('The Hobbit', 9780547928227)
Error: search term not found
Error: multiple keys found
Access multimedia content tttp:///pptooooooooooottooooa///
Chapter summary
Highlights from this chapter incl... | |
corpus-test-287 | 348 14 Files
| Statement | Description |
| data rilelreedlines. | Read all lines of a file. The variable data is a list of strings. |
| wileewrite("Hann) a day!λn") nice | Writes a line to a file. In contrast to print (), the write() function does not automatically newline. append a |
| file.write(["Line 1\n", "Line 2\... | |
corpus-test-288 | GilGs statysty 15
EMPTY CHART
Data Science
Figure 15.1 credit: modification of work by Sebastian Sikora/Flickr, CC BY 2.0
Chapter Outline
15.1 Introduction to data science
15.2 NumPy
15.3 Pandas
15.4 Exploratory data analysis
15.5 Data visualization
15.6 Summary
Introduction
Data Science provides the ability to derive ... | |
corpus-test-289 | 350 15 Data Science
data to extract insights and drive informed decision-making. The data science life cycle is the framework followed by data scientists to complete data science project. The data science life cycle is an iterative process that starts with data acquisition, followed by data exploration. The data acquis... | |
corpus-test-290 | 1.7 Comments 27
b. NameError SyntaxError C.
TRY IT
Three errors
The following program has three errors.
Run the program to find the first error, and correct the corresponding line of code.
Then run the program again to find and correct the second error.
Keep running and correcting the program until no errors are found.... | |
corpus-test-291 | 15.1 Introduction to data science 351
programmer to create documents that contain code, visualizations, and text, making them suitable for data exploration, analysis, and reporting.
Google Colaboratory: Google Colaboratory is a cloud-based Jupyter Notebook environment that allows a programmer to write, run, and share P... | |
corpus-test-292 | 352 15 Data Science
NumPy
Learning objectives
By the end of this section you should be able to
Describe the NumPy library.
Create a NumPy array object.
Choose appropriate NumPy functions to process arrays of numerical data
NumPy library
NumPy (Numerical Python) is a Python library that provides support for efficient nu... | |
corpus-test-293 | 15.2 NumPy 353
b. array-oriented computing
C. memory efficiency
d. all the above
NumPy operations
addition to the ndarray data type, NumPy's operations provide optimized performance for large-scale computation. The key features of NumPy include:
Mathematical operations: NumPy provides a range of mathematical functions ... | |
corpus-test-294 | 354 15 Data Science
arr = ap.array(([]] 2], [1, 21, [1, 2]])
c. import numpy as пp arr = np.array([[], 2], [1, 2], [1, 2]]) T
6. The function np.multiply(arr1, arr2) receives two ndarray objects arr1 and arr2 with the sam dimensions, and performs element-wise multiplication. What is the output of the following code?
im... | |
corpus-test-295 | 15.3 Pandas 355
Data structure: Pandas implements two main data structures
Series: A Series is a one-dimensional labeled array.
DataFrame: A DataFrame is a two-dimensional labeled data structure that consists of columns and rows. A DataFrame can be thought of as a spreadsheet-like data structure where each column repre... | |
corpus-test-296 | 356 15 Data Science
The pd.DataFrame () function takes in a dictionary and converts it into a DataFrame. Dictionary keys will be column labels and values are stored in respective columns.
DataFrame from dictionary
| Description | Example | Output | | Output | Explanation |
| | import pandas as pd | | | | |
| | #... | |
corpus-test-297 | 15.3 Pandas
Output
[2, 3, 4]
| Description | Example | | | | | Explanation |
| | import numpy as пp import pandas pd as | | | | | |
| | data = np.array(I # Create a NumPy array | | | | | |
| | [1, 0, 0], | | A | B | C | |
| DataFrame | [0, 1, 0], | 0 | 1 | 0 | 0 | |
| from a NumPy | # Define column ... | |
corpus-test-298 | 358
| 15 Data Science | | | |
| Description | Example | Output | Explanation |
| DataFrame from CSV a file | import pandas as pd # Read the CSV file into a DataFrame df # Display the DataFrame df | The content of the CSV file will be printed in tabular format. a | The rd.recac_s(() function reads a CSV file into a D... | |
corpus-test-299 | 15.3 Pandas 359
Pandas for data manipulation and analysis
The Pandas library provides functions and techniques to explore, manipulate, and gain insights from the data. Key DataFrame functions that analyze this code are described in the following table.
import pandas as pd
import numpy as пp
# Create a sample DataFrame
... |
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