quiz of chap 9

Author: FahimFBA

Chap_9_Quiz.py

@@ -0,0 +1,125 @@
+__author__ = 'FahimFBA'
+"""
+Question 1
+How are Python dictionaries different from Python lists?
+Python lists are indexed using integers and dictionaries can use strings as indexes
+Python dictionaries are a collection and lists are not a collection
+Python lists can store strings and dictionaries can only store words
+Python lists store multiple values and dictionaries store a single value
+"""
+
+# Answer: Python lists are indexed using integers and dictionaries can use strings as indexes
+
+"""
+Question 2
+What is a term commonly used to describe the Python dictionary feature in other programming languages?
+Closures
+Sequences
+Associative arrays
+Lambdas
+"""
+
+# Answer: Associative arrays
+
+"""
+Question 3
+What would the following Python code print out?
+"""
+
+stuff = dict()
+print stuff['candy']
+
+"""
+The program would fail with a traceback
+0
+-1
+candy
+"""
+
+# Answer: The program would fail with a traceback
+
+"""
+Question 4
+What would the following Python code print out?
+stuff = dict()
+print stuff.get('candy',-1)
+The program would fail with a traceback
+'candy'
+0
+-1
+"""
+
+# Answer: -1
+
+"""
+Question 5
+(T/F) When you add items to a dictionary they remain in the order in which you added them.
+False
+True
+"""
+
+# Answer: False
+
+"""
+Question 6
+What is a common use of Python dictionaries in a program?
+Computing an average of a set of numbers
+Sorting a list of names into alphabetical order
+Building a histogram counting the occurrences of various strings in a file
+Splitting a line of input into words using a space as a delimiter
+"""
+
+# Answer: Building a histogram counting the occurrences of various strings in a file
+
+"""
+Question 7
+Which of the following lines of Python is equivalent to the following sequence of statements assuming that counts is a dictionary?
+if key in counts:
+    counts[key] = counts[key] + 1
+else:
+    counts[key] = 1
+counts[key] = counts.get(key,0) + 1
+counts[key] = counts.get(key,-1) + 1
+counts[key] = (key in counts) + 1
+counts[key] = key + 1
+counts[key] = (counts[key] * 1) + 1
+"""
+
+# Answer: counts[key] = counts.get(key,0) + 1
+
+"""
+Question 8
+In the following Python, what does the for loop iterate through?
+x = dict()
+...
+for y in x :
+    ...
+It loops through the integers in the range from zero through the length of the dictionary
+It loops through all of the dictionaries in the program
+It loops through the values in the dictionary
+It loops through the keys in the dictionary
+"""
+# Answer: It loops through the keys in the dictionary
+
+"""
+Question 9
+Which method in a dictionary object gives you a list of the values in the dictionary?
+items()
+keys()
+values()
+all()
+each()
+"""
+
+# Answer: values()
+
+"""
+Question 10
+What is the purpose of the second parameter of the get() method for Python dictionaries?
+An alternate key to use if the first key cannot be found
+The value to retrieve
+To provide a default value if the key is not found
+The key to retrieve
+"""
+
+# Answer: To provide a default value if the key is not found