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Go to answer 15
What is the meaning of the following two images?
These images were inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at thesame time.
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False. The output is shown in Figure 8 . The keys and the values were switched in the bottom panel of Figure 7 .
| Figure 8 . Answer 15. |
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Get and display values
b'Joe'b'39'
b'333.444.5555'b'married'
b'639'b'male'
Get and display keysb'name'
b'age'b'phone'
b'marital'b'cubicle'
b'gender'Attempt to pop and display two values
b'333.444.5555'no weight
Get and display keys and valuesDatabase length 5
(b'name', b'Joe')(b'age', b'39')
(b'marital', b'married')(b'cubicle', b'639')
(b'gender', b'male')Delete a key/value pair and display again
Database length 4(b'name', b'Joe')
(b'age', b'39')(b'marital', b'married')
(b'gender', b'male') |
Go back to Question 15
True.
Go back to Question 14
False. The output is shown in Figure 5 . The in operator searches for a match in the keys and does not search for a match in the values .
| Figure 5 . Answer 13. |
|---|
Not in dumbDb |
Go back to Question 13
True.
Go back to Question 12
False. The code in Figure 1 produces an error by attempting to store a number as a value. The output (with some text deleted for brevity) is shown in Figure 2 .
| Figure 2 . Answer 11. |
|---|
Traceback (most recent call last):
File "1359-1930-11.py", line 11, in<module>dumbDb[b'aNumber'] = 1234...
raise TypeError("values must be bytes or strings")TypeError: values must be bytes or strings |
Go back to Question 11
True. See The Python Standard Library - 12.5. dbm - Interfaces to Unix "databases" .
Go back to Question 10
True as of 11/09/2014.
Go back to Question 9
True. See comments in sample code at The Python Standard Library - 12.5. dbm - Interfaces to Unix "databases" .
Go back to Question 8
False. The object returned by dbm.open supports the same basic functionality as dictionaries . Keys and their corresponding values can be stored, retrieved, and deleted. The in operator and the keys method are available, as well as get and setdefault .
Go back to Question 7
False. The function named dbm.open can be called to open an existing dbm database file or to create a new dbm database file.
Go back to Question 6
True.
Go back to Question 5
False. dbm is a generic interface to variants of the DBM databases - dbm.gnu or dbm.ndbm . If neither of these modules is installed, the slow-but-simple implementation in module dbm.dumb will be used.
Go back to Question 4
False. As of 11/09/2014, no such warning appears on the referenced webpage. Therefore, it might be concluded that even though shelve has features that are not available in dbm , dbm is the more secure of the two. As a result, this course will concentrate on dbm and ignore shelve .
Go back to Question 3
True as of 11/09/2014.
Go back to Question 2
True as of 11/09/2014.
Go back to Question 1
This section contains a variety of miscellaneous information.
Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possiblefor you to purchase a pre-printed version of the PDF file, you should be aware that some of the HTML elements in this module maynot translate well into PDF.
I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version ofthe module.
In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale onAmazon.com showing me as the author. I neither receive compensation for those sales nor do I know who does receive compensation. If youpurchase such a book, please be aware that it is a copy of a module that is freely available on cnx.org and that it was made andpublished without my prior knowledge.
Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
-end-
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