Chapter 10

Question 1

argv

Answer 1

argv is short for argument vector and is a variable in the sys module which stores a list of command line arguments passed to a program at run time.

Question 2

attribute

Answer 2

A variable defined inside a module (or class or instance – as we will see later). Module attributes are accessed by using the dot operator ( .).

Question 3

command line

Answer 3

The sequence of characters read into the command interpreter in a command line interface

Question 4

command line argument

Answer 4

A value passed to a program along with the program’s invocation at the command prompt of a command line interface (CLI).

Question 5

command prompt

Answer 5

A string displayed by a command line interface indicating that commands can be entered.

Question 6

continue statement

Answer 6

A statement that causes the current iteration of a loop to end. The flow of execution goes to the top of the loop, evaluates the condition, and proceeds accordingly.

Question 7

delimiter

Answer 7

A sequence of one or more characters used to specify the boundary between separate parts of text.

Question 8

directory

Answer 8

A named collection of files, also called a folder. Directories can contain files and other directories, which are refered to as subdirectories of the directory that contains them.

Question 9

dot operator

Answer 9

The dot operator ( .) permits access to attributes and functions of a module (or attributes and methods of a class or instance – as we will see later).

Question 10

file

Answer 10

A named entity, usually stored on a hard drive, floppy disk, or CD-ROM, that contains a stream of characters.

Question 11

file system

Answer 11

A method for naming, accessing, and organizing files and the data they contain.

Question 12

import statement

Answer 12

A statement which makes the objects contained in a module available for use within another module. There are two forms for the import statement. Using a hypothetical module named mymod containing functions f1 and f2, and variables v1 and v2, examples of these two forms include:

import mymod
and

from mymod import f1, f2, v1, v2
The second form brings the imported objects into the namespace of the importing module, while the first form preserves a seperate namespace for the imported module, requiring mymod.v1 to access the v1 variable.

Question 13

Jython

Answer 13

An implementation of the Python programming language written in Java.

Question 14

method

Answer 14

Function-like attribute of an object. Methods are invoked (called) on an object using the dot operator. For example:

>>> s = "this is a string."
>>> s.upper()
'THIS IS A STRING.'
>>>
We say that the method, upper is invoked on the string, s. s is implicitly the first argument to upper.

Question 15

mode

Answer 15

A distinct method of operation within a computer program. Files in Python can be opened in one of three modes: read (‘r’), write (‘w’), and append (‘a’).

Question 16

module

Answer 16

A file containing Python definitions and statements intended for use in other Python programs. The contents of a module are made available to the other program by using the import statement.

Question 17

namespace

Answer 17

A syntactic container providing a context for names so that the same name can reside in different namespaces without ambiguity. In Python, modules, classes, functions and methods all form namespaces.

Question 18

naming collision

Answer 18

A situation in which two or more names in a given namespace cannot be unambiguously resolved. Using

import string
instead of

from string import *
prevents naming collisions.

Question 19

non-volatile memory

Answer 19

Memory that can maintain its state without power. Hard drives, flash drives, and rewritable compact disks (CD-RW) are each examples of non-volatile memory.

Question 20

path

Answer 20

The name and location of a file within a file system. For example:

/usr/share/dict/words
indicates a file named words found in the dict subdirectory of the share subdirectory of the usr directory.

Question 21

pydoc

Answer 21

A documentation generator that comes with the Python standard library.

Question 22

standard library

Answer 22

A library is a collection of software used as tools in the development of other software. The standard library of a programming language is the set of such tools that are distributed with the core programming language. Python comes with an extensive standard library.

Question 23

text file

Answer 23

A file that contains printable characters organized into lines separated by newline characters.

Question 24

volatile memory

Answer 24

Memory which requires an electrical current to maintain state. The main memory or RAM of a computer is volatile. Information stored in RAM is lost when the computer is turned off.