CIS340 CH 7

|infile|

After executing the following code snippet, what part is the file object? infile = open("input.txt", "r") 1. |infile| 2. |"input.txt"| 3. |"r"| 4. |input|

|wordList = line.split()|

Assume that a line has just been read from a file and stored in a variable named |line|. The line contains several words, each of which is separated by one or more spaces. Which of the following statements will store a list of all the words in |wordList|? 1. |wordList = line.split()| 2. |wordList = line.splitlines()| 3. |wordList = line.strip()| 4. |wordList = line.words()|

|outfile.write("Hello\nWorld\n")|

Assume that outfile is a file object that has been opened for writing. Which of the following code segments stores Hello World in the file? 1. |outfile.print("Hello\n", "World\n")| 2. |outfile.write("Hello\n", "World\n")| 3. |outfile.print("Hello\nWorld\n")| 4. |outfile.write("Hello\nWorld\n")|

a file name and mode

When reading a file in Python, you must specify two items: 1. a file name and file properties 2. a file name and mode 3. a file name and size 4. a file name and data type

string

When using the |readline| method, what data type is returned? 1. integer 2. float 3. character 4. string

The finally clause is always executed in this example.

Python's error handling process includes the |finally| clause. In the following code snippet, when is the |finally| clause executed? inputFile = open("lyrics.txt", "r") try : line = inputFile.readline() words = line.split() print(words) finally : inputfile.close() 1. Only when there is an error opening the file. 2. Only when there is an error reading the file. 3. The finally clause is always executed in this example. 4. The finally clause is never executed in this example.

record = inputFile.readline() data = record.split(",") groceryItem = data[0].rstrip() cost = float(data[1])

Suppose an input file contains a grocery list. Each line contains the item name followed by its cost. The item name and cost are separated by a comma. Which statements extract this information correctly? 1. record = inputFile.read(1) data = record.split(,) groceryItem = data[0].rstrip() cost = int(data[1]) 2. record = inputFile.readline() data = record.split() groceryItem = int(data[0]) cost = data[1].rstrip() 3. record = inputFile.readline() data = record.split(",") groceryItem = data[0].rstrip() cost = float(data[1]) 4. record = inputFile.readline() groceryItem = record[0].rstrip() cost = int(record[1])

record = inputFile.readline() data = record.split() name = data[0].rstrip() age = int(data[1])

Suppose the input file contains a person's last name and age on the same line separated by a space. Which statements extract this information correctly? 1. record = inputFile.readline() data = record.split() name = data[0].rstrip() age = int(data[1]) 2. record = inputFile.readline() data = record.split() age = int(data[0]) name = data[1].rstrip() 3. record = inputFile.read(1) data = record.split() name = data[0].rstrip() age = int(data[1]) 4. record = inputFile.readline() name = record[0].rstrip() age = int(record[1])

|while line != "" :|

The following code segment is supposed to read all of the lines from |test.txt| and save them in |copy.txt|. infile = open("test.txt", "r") outfile = open("copy.txt", "w") line = infile.readline() ____________________ outfile.write(line) line = infile.readline() infile.close() outfile.close() Which line of code should be placed in the blank to achieve this goal? 1. |while line == "" :| 2. |while line != "" :| 3. |while line == "\n" :| 4. |while line != "\n" :|

The program displays the contents of the file, but it is double spaced

The following code segment is supposed to read and display the contents of a file. What problem does it have in its current form? infile = open("test.txt", "r") line = infile.readline() while line != "" : print(line) line = infile.readline() infile.close() 1. The program displays all of the lines, except for the first one 2. The program displays all of the lines, except for the last one 3. The program displays the contents of the file, but it is double spaced 4. There is no problem -- the program works as desired

|line = line.rstrip()|

The following program opens |test.txt| and displays its contents. If nothing is placed in the blank, then the contents of the file is displayed double spaced. What should be placed on the blank so that the contents of the file is displayed without the extra blank lines? infile = open("test.txt", "r") line = infile.readline() while line != "" : ____________________ print(line) line = infile.readline() infile.close() 1. |infile = infile.lstrip()| 2. |infile = infile.rstrip()| 3. |line = line.lstrip()| 4. |line = line.rstrip()|

Comma-Separated Values (CSV)

What portable file format is commonly used to export data from a spreadsheet so that it can be read and processed by a Python program? 1. Comma-Separated Values (CSV) 2. Graphics Interchange Format (GIF) 3. Hypertext Markup Language (HTML) 4. Portable Spreadsheet Format (PSF)

Integer

What type of value is returned by the expression |ord("A")|? 1. Integer 2. Floating Point Number 3. String 4. List

|["Michigan", "Maine", "Minnesota", "Montana", "Mississippi"] |

What will be stored in |substrings| after the following code snippet has run? states = "Michigan,Maine,Minnesota,Montana,Mississippi" substrings = states.split(",") 1. |"Michigan,Maine,Minnesota,Montana,Mississippi" | 2. |["Michigan", "Maine", "Minnesota", "Montana", "Mississippi"] | 3. |["Michigan,Maine,Minnesota,Montana,Mississippi"] | 4. |"Michigan" |

write, print

What method(s) can be used to write to a file? 1. write, print 2. out, print 3. write, out 4. post, write

write

In the following code snippet, what does the |"w"| represent? outfile = open("output.txt", "w") 1. wrapper 2. write 3. width 4. web

The program will raise an exception

Assume that your program is started with the following command: python myProgram.py the quick brown fox What will be displayed by the following statement? print(sys.argv[5]) 1. |brown| 2. |fox| 3. A blank line 4. The program will raise an exception

|myProgram.py|

Assume that your program is started with the following command: python myProgram.py -z 100 What will be displayed by the following statement? print(sys.argv[0]) 1. |python| 2. |myProgram.py| 3. |-z| 4. |100|

open the file

Before accessing a file, the program must: 1. name the file 2. read the file 3. open the file 4. close the file

file = open("c:\\users\\user1\\states.dat", "r")

Consider a program that wants to read a file from the absolute path |c:\users\user1\states.dat|. What statement allows you to read this file? 1. file = open("c:\\\users\\\user1\\\states.dat", "r") 2. file = open("c:\users\user1\states.dat", "r") 3. file = open("..\\states.dat", "r") 4. file = open("c:\\users\\user1\\states.dat", "r")

|csvWriter.writerow([1, 2, 3, 4])|

Consider the following code segment: from csv import writer outfile = open("newdata.csv", "w") csvWriter = writer(outfile) What statement should be added to the end of this code segment so that it will write a row of values to the file? 1. |csvWriter.writerow(1, 2, 3, 4)| 2. |csvWriter.writerow([1, 2, 3, 4])| 3. |outf.write(1, 2, 3, 4)| 4. |outf.write([1, 2, 3, 4])|

|os.path.exists(filename)|

Consider the following code segment: import os filename = input("Enter the name of a file: ") if ____________________ : print("That file exists!") else: print("That file does not exist.") This code segment is supposed to print an appropriate message indicating whether or not the file specified by the user exists. What code should be placed in the blank so that the code segment performs its intended task? 1. |filename != ""| 2. |os.path.exists()| 3. |os.path.exists() == filename| 4. |os.path.exists(filename)|

|"hello", "world!"|

Consider the following code segment: line = "hello world!" parts = line.split() print(parts) What is displayed when this code segment runs? 1. |hello,world!| 2. |hello world!| 3. |"hello", "world!"| 4. |["hello", "world!"]|

|WX|

Consider the following code segment: print("W", end="") try : inFile = open("test.txt", "r") line = inFile.readline() value = int(line) print("X", end="") except IOError : print("Y", end="") except ValueError : print("Z", end="") What output is generated when this program runs if |test.txt| is opened successfully and its first line contains the number 5? 1. |W| 2. |WX| 3. |WXY| 4. |WXYZ|

|WZ|

Consider the following code segment: print("W", end="") try : inFile = open("test.txt", "r") line = inFile.readline() value = int(line) print("X", end="") except IOError : print("Y", end="") except ValueError : print("Z", end="") What output is generated when this program runs if |test.txt| is opened successfully and its first line contains the |hello world|? 1. |WX| 2. |WY| 3. |WZ| 4. |WXZ|

|WY|

Consider the following code segment: print("W", end="") try : inFile = open("test.txt", "r") line = inFile.readline() value = int(line) print("X", end="") except IOError : print("Y", end="") except ValueError : print("Z", end="") What output is generated when this program runs if |test.txt| is not opened successfully? 1. |WX| 2. |WY| 3. |WZ| 4. |WXY|

except IndexError :

Consider the following code segment: try : inputFile = open("lyrics.txt", "r") line = inputFile.readline() words = line.split() print(words[len(words)]) _____________________ print("Error.") The statement |print(words[len(words)])| will raise an exception. What should be placed in the blank so that this exception will be caught and the error message will be displayed? 1. except RuntimeError : 2. except EnvironmentError : 3. except IOError : 4. except IndexError :

|done = True|

Consider the following code segment: done = False while not done : try : filename = input("Enter the file name: ") inFile = open(filename, "r") ____________________ except IOError : print("Error: File not found.") It is supposed to keep on prompting the user for file names until the user provides the name of a file that can be opened successfully. What line of code should be placed in the blank to achieve this goal? 1. |done = False| 2. |done = True| 3. |done = inFile| 4. |done = not inFile|

|raise RuntimeError|

Consider the following code segment: line = input() try: ... if line == "": ____________________ ... except RuntimeError: print("A blank line was encountered.") This code segment is supposed to print out |A blank line was encountered| when a blank line is entered by the user. What code should be placed in the blank so that it will accomplish this goal? 1. |except RuntimeError| 2. |raise RuntimeError| 3. |RuntimeError(raise)| 4. |RuntimeError(except)|

except IOError :

Consider the following code segment: try : inputFile = open("lyrics.txt", "r") line = inputFile.readline() print(line) _____________________ print("Error") What should be placed in the blank so that the program will print |Error| instead of crashing if an exception occurs while opening or reading from the file? 1. except RuntimeError : 2. except EnvironmentError : 3. except IOError : 4. except IndexError :

A tuple containing the slope, intercept and correlation coefficient for the data sets.

Consider the following function call for computing a linear regression: result = scipy.stats.linregress(data1, data2) What is stored in result when this function call completes? 1. A Boolean value indicating whether or not the regression was completed successfully. 2. A floating point number between -1 and 1 that indicates the amount of correlation between the data sets. 3. A list containing the mean and median values of both data sets. 4. A tuple containing the slope, intercept and correlation coefficient for the data sets.

The existing file is emptied

In the following code snippet, what happens if the |"output.txt"| file already exists? outfile = open("output.txt", "w") 1. Any new data is appended to the end 2. The existing file is emptied 3. Nothing, this statement is ignored 4. An error message is displayed

An empty file is created

In the following code snippet, what happens if the |"output.txt"| file does not exist? outfile = open("output.txt", "w") 1. An error message is displayed 2. An empty file is created 3. Nothing, this statement is ignored 4. A new file is created with at least one record

"rb", "wb"

What modes are used to read and write a binary file? 1. "r", "w" 2. "-r", "-w" 3. "rb", "wb" 4. "-rb", "-wb"

H

Given a text file |quote.txt| that contains this sentence: Home computers are being called upon to perform many new functions, including the consumption of homework formerly eaten by the dog. ~Doug Larson What is the result of this code snippet: inputFile = open("quote.txt", "r") char = inputFile.read(1) while char != "" : print(char) char = inputFile.read(1) inputFile.close() 1. Home computers are being called upon to perform many new functions, including the consumption of homework formerly eaten by the dog. ~Doug Larson 2. each character of the quote is printed on a separate line 3. H 4. o

|argv| list

Given the following command line, where are the arguments stored? python program.py -v input.dat 1. user defined list 2. |argv| list 3. |input.dat| 4. |program.py|

Move the /file marker/ prior to a read or write operation.

How can you read from a file starting at a designated position in it? 1. Open the file for sequential access. 2. Move the /file marker/ prior to a read or write operation. 3. You can't. Python only allows you to start reading at the beginning of a file. 4. Use the |readline(position)| method.

Selecting "Run" in the development environment

How is a program executed or started from the command line? 1. Selecting "Run" in the development environment 2. Clicking an icon 3. Typing the name of the program at the prompt in a terminal window 4. Python programs cannot be started from the command line

0 - 255

If a Byte consists of 8 Bits, what is the min and max values of one Byte? 1. 0 - 255 2. 1 - 256 3. 0 - 256 4. 1 - 255

argv[0]: "program.py" argv[1]: "-r" argv[2]: "input.dat" argv[3]: "output.dat"

If a program is invoked with |python program.py -r input.dat output.dat|, what are the elements of |argv|? 1. argv[0]: "-r input.dat output.dat" 2. argv[1]: "-r" argv[2]: "input.dat" argv[3]: "output.dat" 3. argv[0]: "program.py" argv[1]: "-r" argv[2]: "input.dat" argv[3]: "output.dat" 4. argv[0]: "-r" argv[1]: "input.dat" argv[2]: "output.dat"

Monday! Tuesday. Wednesday?

In the code snippet below, if the file contains the following words: |Monday! Tuesday. Wednesday?| stored one per line, what would be the output? infile = open("input.txt", "r") for word in infile : word = word.lstrip(".!") print(word) 1. Monday Tuesday Wednesday 2. Monday Tuesday Wednesday 3. Monday! Tuesday. Wednesday? 4. Monday Tuesday Wednesday?

Monday Tuesday Wednesday?

In the code snippet below, if the file contains the following words: |Monday! Tuesday. Wednesday?| stored one per line, what would be the output? infile = open("input.txt", "r") for word in infile : word = word.rstrip(".!\n") print(word) 1. Monday Tuesday Wednesday 2. Monday Tuesday Wednesday 3. Monday! Tuesday. Wednesday 4. Monday Tuesday Wednesday?

apple pear banana

In the code snippet below, if the file contains the following words: |apple, pear,| and |banana| stored one per line, what would be the output? infile = open("input.txt", "r") for word in infile : word = word.rstrip() print(word) 1. apple pear banana 2. apple pear banana 3. apple pear banana 4. apple, pear, banana

read

In the following code snippet, what does the |"r"| represent? infile = open("input.txt", "r") 1. replace 2. recursive 3. random 4. read

|ZeroDivisionError |

It is good programming practice to plan for possible exceptions and provide code to handle the exception. Which exception must be handled to prevent a divide by zero logic error? 1. |ValueError | 2. |TypeError | 3. |ArithmeticError | 4. |ZeroDivisionError |

|readline() |

Once a file has been opened, what method is used to read data from a file? 1. |readline() | 2. |readfile() | 3. |readln() | 4. |open() |

\n

The |readline| method reads text until an end of line symbol is encountered, how is an end of line character represented? 1. \r 2. \t 3. "" 4. \n

inFile.close()

What code should be added to the end of the following code segment to ensure that |inFile| is always closed, even if an exception is thrown in the code represented by |. . .| ? inFile = open("test.txt", "r") try : line = inFile.readline() . . . 1. inFile.close() 2. always : inFile.close() 3. ensure : inFile.close() 4. finally : inFile.close()

|IndexError|

What exception is raised by the following code segment? data = ["A", "B", "C", "D"] print(data[4]) 1. |IndexError| 2. |IOError| 3. |ValueError| 4. No exception is raised by the code segment

A run-time error occurs because the file does not exist.

What happens if you try to open a file for reading that doesn't exist? 1. A new file is created and opened. 2. A run-time error occurs because the file does not exist. 3. The statement is ignored. 4. An environment error occurs.

a run-time error occurs because the file does not exist

What happens in the following code snippet? infile = open("", "r") 1. a new file object is created 2. a run-time error occurs because the file does not exist 3. nothing, the statement is ignored 4. a default file name is used |"inputfile"|

The program raises an exception

What happens when the following code segment executes if |test.txt| does not exist? infile = open("test.txt", "r") 1. The file |test.txt| is created as a new empty file 2. The program raises an exception 3. All attempts to read from the file return an empty string 4. All attempts to read from the file return random values

The file |test.txt| is created as a new empty file

What happens when the following code segment executes if |test.txt| does not exist? outfile = open("test.txt", "w") 1. The file |test.txt| is created as a new empty file 2. The program ends with an exception 3. All attempts to write to the file succeed but do not save any

apple pear banana

What is output by the following code segment when |input.txt| contains the following words: |apple|, |pear,| and |banana| stored one per line? infile = open("input.txt", "r") for word in infile : print(word) 1. apple pear banana 2. apple pear banana 3. apple pear banana 4. apple, pear, banana

""

What is returned when the |readline| method reaches the end of the file? 1. \r 2. \t 3. "" 4. \n

|["Michigan,Maine,Minnesota,Montana,Mississippi"] |

What is stored in |substrings| after the following code snippet has run? states = "Michigan,Maine,Minnesota,,Montana,Mississippi" substrings = states.split(",") 1. |"Michigan,Maine,Minnesota,Montana,Mississippi" | 2. |["Michigan"] | 3. |["Michigan,Maine,Minnesota,Montana,Mississippi"] | 4. |["Michigan","Maine","Minnesota","","Montana","Mississippi"] |

|a|

What is the name of the file object variable in the following code segment? a = open("b.txt", "r") 1. |a| 2. |b| 3. |b.txt| 4. |r|

5

What is the result of the variable |position| after the following code snippet is executed? inFile.seek(0) inFile.seek(8, SEEK_CUR) inFile.seek(-3, SEEK_CUR) position = inFile.tell() 1. 0 2. 8 3. 5 4. -3

Python cannot iterate over the file twice without closing and reopening the file

What is wrong with the following code snippet that is supposed to print the contents of the file twice? infile = open("input.txt", "r") for sentence in infile : print(sentence) for sentence in infile : print(sentence) 1. Python cannot iterate over the file twice without closing and reopening the file 2. A run-time error occurs because the file does not exist 3. Nothing, the code prints the contents two times 4. The program cannot use the variable |sentence| twice

The file has only been opened for writing, not reading.

What is wrong with the following code snippet: file = open("lyrics.txt", "w") line = file.readline() words = line.split() print(words) file.close() 1. The file has only been opened for writing, not reading. 2. The file name is invalid. 3. The program cannot run without a try/catch statement. 4. The split method has not been used correctly.

close()

What method ensures that the output has been written to the disk file? 1. commit() 2. write() 3. close() 4. complete()

The file name might be too long

When your program contains logic to read one or more files, which of the following statements is NOT true about the error handling logic needed: 1. The file might not exist 2. The file name might be too long 3. The file might contain invalid data 4. All files must be opened and closed prior to program termination

UTF-8

Which character encoding standard uses sequences of between 1 and 4 bytes to represent a huge number of different characters? 1. ASCII 2. CSV 3. Extended ASCII 4. UTF-8

|average|

Which function is *not* part of the Python |statistics| module? 1. |mean| 2. |median| 3. |stdev| 4. |average|

for line in infile : print(line)

Which of the following code segments will display all of the lines in the file object named |infile|, assuming that it has successfully been opened for reading? 1. for infile in line : print(line) 2. for line in infile : print(line) 3. while infile in line : print(line) 4. while line in infile : print(line)

fileName.write("Good Bye")

Which of the following file operations is NOT valid for reading a binary file? 1. fileName = open("input.dat", "r") 2. fileName.close() 3. fileName.write("Good Bye") 4. fileName = open("input.dat", "rw")

|open|

Which of the following is *not* a function that resides in Python's |os| module? 1. |chdir| 2. |open| 3. |remove| 4. |rename|

|TryError |

Which of the following is NOT a valid exception in Python? 1. |OverflowError | 2. |TryError | 3. |IOError | 4. |IndexError |

|sentence.split() |

Which of the following methods provides a way to split the contents of the string |sentence| into a list of individual words? 1. |sentence.split() | 2. |sentence.strip() | 3. |sentence.splice() | 4. |sentence.separate() |

s.strip(".!?;:")

Which of the following methods strips specified punctuation from the front or end of each string (|s|)? 1. s.lstrip(".!?;:") 2. s.rstrip(".!?;:") 3. s.strip(".!?;:") 4. s.strip()

inputFile.readline(5)

Which of the following statements is NOT valid for reading from a file: 1. inputFile.readline() 2. inputFile.read() 3. inputFile.readline(5) 4. inputFile.read(5)

|inFile.seek(-4, SEEK_CUR)|

Which of the following statements moves the file marker 4 bytes earlier in a binary file with its file object stored in |inFile|? 1. |inFile.seek(-4, SEEK_CUR)| 2. |inFile.seek(4, SEEK_CUR)| 3. |inFile.reverse(-4, SEEK_CUR)| 4. |inFile.reverse(4, SEEK_CUR)|

|inFile = open("test.dat", "rb")|

Which of the following statements opens a binary file for reading? 1. |inFile = open("test.dat", "r")| 2. |inFile = open("test.dat", "rb")| 3. |inFile = open("test.dat", "binary")| 4. |inFile = open("test.dat", "readbinary")|

infile = open("myfile.txt", "r")|

Which of the following statements opens a text file for reading? 1. |infile = open("myfile.txt", "r")| 2. |infile = open("myfile.txt", "rw")| 3. |infile = open("myfile.txt", "read")| 4. |infile = open("myfile.txt", "reading")|

|inf = open("input.txt")|

Which of the following statements should be used to open a file that might contain special characters (such as accents, Greek letters or musical symbols) for reading? 1. |inf = open("input.txt")| 2. |inf = open("input.txt", "r")| 3. |inf = open("input.txt", "r", "utf-8")| 4. |inf = open("input.txt", "r", encoding="utf-8")|

|x = inFile.tell()|

Which of the following statements stores the current position of the file marker for |inFile| into |x|? 1. |x = inFile.currentPos()| 2. |x = inFile.position()| 3. |x = inFile.read()| 4. |x = inFile.tell()|

inputFile.read(1)

Which statement below can be used to read data from a file one character at a time? 1. inputFile.get(1) 2. inputFile.read(1) 3. inputFile.split(1) 4. inputFile.open(1)

|from re import *|

Which statement imports all of the functions in Python's regular expression library? 1. |from re import *| 2. |from regex import *| 3. |from reg_exp import *| 4. |from regular_expression import *|

|infile.close()|

Which statement is used to close the file object opened with the following statement? infile = open("test.txt", "r") 1. |close(infile)| 2. |close("test.txt")| 3. |infile.close()| 4. |infile.close("test.txt")|

|from sys import argv|

Which statement must appear in a program before the command line arguments can be accessed? 1. |from commandline import argv| 2. |from argv import commandline| 3. |from sys import argv| 4. |from argv import sys|

outfile.write("Today \nis \nthe \nfirst \nday \nof \nthe \nrest \nof \nyour \nlife")

Which statement(s) writes the sentence |"Today is the first day of the rest of your life"| to a file with one word on each line? 1. outfile.write("Today is the first day of the rest of your life") 2. outfile.write("Today \nis \nthe \nfirst \nday \nof \nthe \nrest \nof \nyour \nlife") 3.outfile.write(Today is the first day of the rest of your life) 4. outfile.writeline("Today \nis \nthe \nfirst \nday \nof \nthe \nrest \nof \nyour \nlife")

A bubble chart

Which type of chart can be used to represent the relationship between three dimensional data? 1. A bar chart 2. A bubble chart 3. A histogram 4. A pie chart