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| h03 |
| CS8 W19 |
| Name: | ||||
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| (as it would appear on official course roster) | ||||
| Umail address: | @umail.ucsb.edu | section |
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| Optional: name you wish to be called if different from name above. | ||||
| Optional: name of "homework buddy" (leaving this blank signifies "I worked alone" | ||||
h03: Perkovic 2.4-2.5 (Objects, Classes, types, libraries)
| ready? | assigned | due | points |
|---|---|---|---|
| true | Thu 01/17 02:00PM | Wed 01/23 09:00AM |
You may collaborate on this homework with AT MOST one person, an optional "homework buddy".
MAY ONLY BE TURNED IN IN THE LECTURE/LAB LISTED ABOVE AS THE DUE DATE,
OR IF APPLICABLE, SUBMITTED ON GRADESCOPE. There is NO MAKEUP for missed assignments;
in place of that, we drop the lowest scores (if you have zeros, those are the lowest scores.)
READING ASSIGNMENT
Please read Perkovic 2.4-2.5 (Objects, Classes, types, libraries). Then complete these problems and turn in your completed homework during your registered lab section..
(10 pts) Please fill in the information at the top of this homework sheet, including your name and umail address. If the other two items apply, please fill them in as well. Please do this every single time you submit homework for this class. It is important to fill in both name and umail every time, since handwriting is sometimes difficult to decipher. Having both helps us ensure you get credit for your work.
DO NOT staple, paper clip, spit-fold-and-tear, or do ANYTHING that would make it difficult to automatically feed your paper through a scanner.
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As discussed in Section 2.4, the
type()function returns the type of a Python value. When you pass a variable such asx,type(x)returns the type of the value that the variablexcurrently refers to.Assume that the following assignment statement has been executed:
schools=["UCSB","Stanford","UCSD","Cal Poly"]What will each of the expressions below evaluate to? As a reminder, strictly speaking, Python will print types in the format
<class 'int'>,<class 'float'>,<class 'str'>, etc. so please use exactly that format for full credit.Points Expression Result Points Expression Result (4 pts) type(3)(4 pts) type(1+2.5)(4 pts) type('3')(4 pts) type(2 * "3")(4 pts) type("3.5")(4 pts) type((3,3))(4 pts) type(3.5)(4 pts) type(schools)(4 pts) type([3,5])(4 pts) type(schools[0]) -
(10 pts) Assume that
casesis the name of a variable with afloatvalue that you want to convert to an integer value. Write a Python expression that convertscasesto an integer (throwing away any fractional part) -
(10 pts) Assume that
courseNumis an integer that represents the numeric part of a course number (e.g. 3, 8, 130, 16, 24). Write a Python expression that convertscourseNumto an string (i.e.<class 'str'>in Python) -
(10 pts) If you want to check whether x is greater than 10, and y is greater than 5, you can write the Python expression
(x > 10) and (y > 5)If
xhas the value20, andyhas the value17, this evaluates toTrue.But what if we accidentally wrote it as:
(x > 10) + (y > 5)What would this expression evaluate to, assuming the same values for
xandy)? (The answer requires you to read the section carefully, and then apply what you have learned. I suggest you try that first before trying it at the Python command line.) - Both Sections 2.4 and 2.5 mention a type of function that is called a constructor.
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(5 pts) In general, what do constructors do? (Don’t give an answer that is specific, for instance, to only the constructor for the
intdata type). -
(5 pts) Before using the constructor for a
Fractionobject, a particular line of Python code must be written. What is that line of code? (Be very careful about spelling and upper vs. lower case.) -
(10 pts) Assuming that line of code has been typed (the one mentioned in the previous question), how do you create a
Fractionobject that holds the fraction (i.e., “four fifths”), and makes the variableratiorefer to that object?
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