EXAM

Question 1

printing the contents of a file containing two lines read with “readlines()” results in what?

Answer 1

[‘Line01\n’, ‘Line02’]

Question 2

printing the contents of a file containing two lines read in with “read()” results in what?

Answer 2

Line01\nLine02

Question 3

Opening an existing text file with the option ‘w’ and then “write”ing some text to the file does what

Answer 3

Writes over the contents of the existing file.

Question 4

If a file is opened with the option ‘a’ but the file doesn’t exist, what is returned?

Answer 4

File text_file.txt will be created if it does not exist

Question 5

If a file is opened with the option ‘r’ but the file doesn’t exist, what is returned?

Answer 5

Error message.

Question 6

“ATGCATGC” return the results when the “GC” is replaced with “U”

Answer 6

ATUATU

Question 7

What is the “len” of a sequence when you split “ATGCATGC” at “A”

Answer 7

3, first A results in a space.

Question 8

stringvariable.find(‘string’) method returns what?

Answer 8

The index of the first occurrence of the substring if found or -1 if not found

Question 9

string = [“Python”, “is”, “fun”] print(““.join(string)) returns what?

Answer 9

Python is fun - string join() method returns a string by joining all the elements of an iterable (list, string, tuple)

Question 10

string.split() does what to this object, string = “Good Morning to you”
[“Good”, “Morning”, “to”, “you”] text.split() -

Answer 10

splits string into a list of substrings at each space character, text.split(‘,’) splits at commas,

Question 11

Class instantiation uses function notation that returns a new instance of the class. For example
tobject = Grades(1234, 5007) does what?

Answer 11

creates a new instance of the class and assigns this object to the local variable tobject.

Question 12

How does class inheritance work?

Answer 12

Declare your class followed by parentheses and then list any classes that your class inherits from. In a function definition, parentheses after the function name represent arguments that the function accepts. In a class definition the parentheses after the class name instead represent the classes being inherited from. The second class has access to all the methods in the inherited class.

Question 13

f1= Fraction(1,2)
f2= Fraction(2,3)
f3 = f1 + f2
print(f3.num)
returns 7, why?

Answer 13

The Fraction module is a built in class with a __add__ method which is = to the arithmetic function +
1/2 + 2/3 = 3/6+4/6=7/6
7 = num, 6 = den
f3.num calls the add function and the numerator is 7

Question 14

If head = 0 in your Class and you instantiate the object with other variables, what does print(IList.head) return?

Answer 14

0 because the variable head = 0 in iList. Despite IList class being called in the previous line with a list of numbers which would set head to 4, that doesn’t persist because it isn’t saved when iList is called again. Rather than printing out a variable, the print command here calls the class with no input attributes so head is equal to the default value set in the class.

Question 15

How do you call a method inside a class. ex. print(new_emp.getDept()) vs. call an attribute in a class by print(new_emp.dept)

Answer 15

We invoke a method by first typing in the name of the object we are referencing, followed by a dot (.), followed by the method with parenthesis.

Question 16

What position does this command return in an XML file?
find(“.//country[1]”).attrib[“name”]

Answer 16

Returns the “name” attribute of the first country listed because parsing in XML starts at position 1 unlike JSON and CSV which starts at position 0.
- find(“.//country[2]”).attrib[“name”]
- finds the second country in an XML file.

Question 17

When you open a csv file with csv.reader what is the first row read?

Answer 17

The first row read is the header row.

Question 18

When you open a csv file with csv.dictreader what is the first row read?

Answer 18

The first row read when opened with dictreader is the first row of data.

Question 19

print(xmlRoot.find(./country[@name=’Panama’]/rank”).text) does what?

Answer 19

Looks in country to find the attribute name which equals Panama and returns the rank text value.

Question 20

What does this do?
if neighbor.get(“direction”) == “E”:
cname = neighbor.get(“name”)
Print(cname)

Answer 20

Finds the neighbor tag where the direction attribute value is E and returned the name attribute as cname

Question 21

XML file positions start with which number?

Answer 21

[1] - yes it is true. XML unlike JSON start position with 1 not 0

Question 22

CSV file positions start with which number?

Answer 22

[0] - Most objects in python start position counting with [0, 1, 2, 3…]

Question 23

Learning by associating stimulus and response is called:

Answer 23

classical conditioning

Question 24

Computationally intractable problems are problems that are:

Answer 24

not solvable with existing computational tools

Question 25

All possible outcomes of a problem is called

Answer 25

problem space

Question 26

Conterfactual thinking is what?

Answer 26

Thinking about alternate outcome if an event in past had been different

Question 27

Explain Type 1 vs Type 2 reasoning.

Answer 27

use type 1 reasoning when:
You are very experienced
Have repeatedly seen the same pattern before.
Need quick results
When you are aware of possible biases and control for them.
When the risk of not acting quickly is worse or equal to making an error.

You should use type 2 reasoning when:
the problem involves a novel choice which you have never seen.
there is a strong confirmation bias, availability bias, or other human judgement error towards the situation.
the intuitive answer might lead you in the wrong direction.
the problem is very complex and needs to be broken down into sub-problems.
There is time to test hypothesis and eliminate possibilities.

Question 28

What makes a well defined problem?

Answer 28

1. an initial/starting state
2. a clear end or goal state
3. a set of allowable moves or actions to change states

one where the entire problem space is mapped out, decision rules which link the conditions to actions are available. The desired results are very clear and specific outcomes.

Question 29

Define metadata with an example. Provide a healthcare use case where the metadata is used.

Answer 29

Metadata is data about data for example in healthcare, we often refer to demographics as a data grouping. Patient demographics refers to multiple data elements such as race, ethnicity, gender, age at diagnosis, income, married or not. The properties of these data elements, what each of these data elements mean, what values are allowed in the fields, whether they are binned, how the fields are defined is the metadata. The actual data would be the values for an individual patient such as white, Hispanic, 42, 50k-100k, single. In this way, the metadata defines the data that is being collected.

Question 30

Define secondary analysis of healthcare data

Answer 30

Raw data is the actual data collected on a patient while secondary analysis is data that can be derived from the primary raw data. For example if a patient is on a drug for hypertension then you know that they have hypertension, similarly for diabetes drugs, you can infer the diagnosis based on the drug prescribed. Secondary analysis is the process to derive additional data from the primary data such as the example just described using the primary data = drug prescribed to determine the secondary data = diagnosis.

Question 31

Data Acquisition is:

Answer 31

Extracting the data in a desired format

Question 32

Which of the following is not core to Data Science? Data Intelligence, Data Wrangling, Data Analysis, Data Quality

Answer 32

Data Intelligence is not core to Data Science.

Question 33

Compare two subsets of data to determine if any relationship exists, that is:

Answer 33

Data Analysis

Question 34

By decreasing the time spend in ICU, evaluate the effect in cost savings is an example of what type of analysis?

Answer 34

causative analysis

Question 35

Checking to see if there are missing value in the blood glucose monitoring would be an example of what data science action?

Answer 35

Data Manipulation is the answer provided - perhaps because it includes data quality.

Question 36

ATGCATGC
What is at position [-3] + [3] ?

Answer 36

TC ; counting backwards starts at -1, counting forward starts at 0

Question 37

When converting from a float to an integer what happens to a decimal like int(float(0.98))) ?

Answer 37

It becomes 0 because when converting from float to integer, the number gets truncated (decimal parts are removed). Since 0.99 losses everything to the right of the decimal all that is left is the 0

Question 38

For the following code to work without error, which of the following condition must be met?

fname = open(“/opt/data/text_file.txt”, “w”)

(a.)File text_file.txt may or may not exist in the directory
(b.)File text_file.txt must be a binary file
(c.)File text_file.txt must be empty
(d.)File text_file.txt must not exist, as it is newly created

Answer 38

a

Question 39

For the following code to work without error, which of the following condition must be met?

fname = open(“/opt/data/text_file.txt”, “a”)

(a.)File text_file.txt will be created it does not exist
(b.)File text_file.txt must be binary
(c.)File text_file.txt must not be empty
(d.)File text_file.txt will be replaced with new file.

Answer 39

a

Question 40

Consider the text_file.txt with following contents
Line01
Line02

Provide the exact output of the following python script

1
2 fname = open(“/opt/data/text_file.txt”, “a”)
3 ftext = fname.read()
4 fname.close()
5 print(ftext)
6

(a.)Line01\nLine02
(b.)Line01
(c.)Line01 Line02
(d.)Line01Line02

Answer 40

a

Question 41

For the following code to work without error, which of the following condition must be met?

fname = open(“/opt/data/text_file.txt”, “r”)

(a.)File text_file.txt must exist in the directory
(b.)File text_file.txt must be a binary file
(c.)File text_file.txt should not exist, and it will be created by the program
(d.)File text_file.txt should not be empty

Answer 41

a

Question 42

Consider that a file text_file.txt exists at /opt/data/text_file.txt and following python program

1
2 fname = open(“/opt/data/text_file.txt”, “w”)
3 ftext = fname.write(“Last Line”)
4 fname.close()
5

(a.)text_file.txt will be replaced with new contents
(b.)”Last Line” will be appended to the file
(c.)There will be an error
(d.)Nothing will be written to the file

Answer 42

a