# a1.py
# PUT YOUR NAME(S) AND NETID(S) HERE
# Sources/people consulted: FILL IN OR WRITE "NONE"
# PUT DATE YOU COMPLETED THIS HERE
# Skeleton by Prof. Lee (cs1110-prof@cornell.edu), Feb 14 2018
"""
Functions for finding whether a class is open or closed on a roster.
We use "backwards single quotes" --- like this: `hi there` --- in the
docstrings below to visually set off variable names.
"""
# Helper function
def before_first_double_quote(text):
"""Returns: the part of string `text` right up to but not including
the first double-quote.
Precondition: string `text` contains at least one double-quote.
Example: before_first_double_quote('abd"def') returns the string
abd
"""
pass # IMPLEMENT THIS FUNCTION
# Helper function
def after(tag, text):
"""Returns: all of string `text` that occurs just after the first
occurrence of string `tag` in `text`.
Preconditions:
`text` [str] contains an instance of `tag`
`tag` [str] has length > 0
Example: if `tag` is the string
<a id="c111">
and `s` is the string
start <a id="c111">xthis that the other
then this functions returns the string
xthis that the other
"""
pass # IMPLEMENT THIS FUNCTION
def open_status(class_num, data):
"""Returns the open-ness status of class `class_num` according to `data`.
`class_num`: string version of a class number, e.g., "10776" at Cornell.
`data`: a string whose preconditions are easiest explained by example.
Suppose `class_num` is "10775".
Then, `data` must contain somewhere within it a single occurrence of
<a id="c10775">
and this is followed by text where the first occurrence of the string
open-status-
(the ending hyphen is important) is one of
open-status-open"
or
open-status-closed"
or any string of the form
open-status-???"
(the ending double-quote is important to notice)
where the ??? stands for a sequence of characters not containing quotes
that represents the open-ness status of the course. (For example, maybe
there is such a thing as open-status-waitlist")
This function returns whatever ??? is.
Example: if `class_num` is "10775", and `data` is the string
<a id="c10775"> fa-circle open-status-open"></i></span>
then this function returns the string
open
Example: if `class_num` is "10775", and `data` is the string
dum dee dum <a id="c10775"> open-stat open-status-CLOSED" tral la la
then this function returns the string
CLOSED
Example: if `class_num` is "432" and `data` is the string
<a id="c4321"> ha open-status-open" <a id="c432"> open-status-never!""
then this function returns the string
never!
(The exclamation point must be included.)
Example: if `class_num` is "432" and `data` is the string
<a id="c432"> ho open-status-open" <a id="c432"> open-status-nope."
then this function returns the string
nope.
(The number of spaces matters between the `a` and the `id` matters.)
"""
# STUDENTS: YOUR IMPLEMENTATION MUST CALL AND MAKE USE OF THE RETURN
# VALUE OF helper functions `after` and `before_first_double_quote`
# (or new helper functions you write that call them).
# HINT for how to find where to begin searching in the string.
# It might not work to run data.index("10775") to find the location
# of '<a id="c10775">' in data. (See test case 2 in
# a1test.test_open_status to see why not.)
# But the following is a legal expression:
# data.index('<a id="c' + "10775" + '">')
# as is
# data.index("<a id=\"c" + "10775" + "\">")
# Can you adapt either idea to your situation?
pass # IMPLEMENT THIS FUNCTION
def label(class_num, data):
"""Returns, as a single string, the common name, component and component
number for class `class_num` according to `data`.
`class_num`: string version of a class number, e.g., "10776" at Cornell.
`data`: a string whose preconditions are easiest explained by example.
Suppose `class_num` is "10782".
Then, `data` matches the pattern
... <a id="c10782"> ... class="course-repeater">CS 1110 ...
data-ssr-component="DIS" data-section="208"
And the function should return the string
CS 1110 DIS 208
with no beginning or trailing whitespace.
That is, `data` must contain somewhere within it a single occurrence of
<a id="c10782">
and this is followed by text where the first occurrence of the string
class="course-repeater">
(the ending quote and angle-bracket is important) is followed by the
common name of the course, and then the string
and the first occurrence of the string
data-ssr-component="
is followed by the component, followed by a double-quote,
and the first occurrence of the string
data-section="
is followed by the component number followed by a double-quote.
The function returns the string formed by concatenating the common
name, then a space, then the component, then a space, then the
component number.
"""
pass # IMPLEMENT THIS FUNCTION
# STUDENTS: YOUR IMPLEMENTATION MUST CALL AND MAKE USE OF THE RETURN
# VALUE OF helper functions `after` and `before_first_double_quote`
# (or new helper functions you write that call them).
# HINT: You may find it easier to develop this function incrementally,
# That is, consider the following outline.
# 1. Just get the function to store the common name in a variable.
# 2. Once that's working, get it to store the component in another variable.
# 3. Then, get it to store the component number in a third variable.
# 4. Figure out how to combine the values of the three variables to
# get the desired return value