Collection of Data and File Operation

Question 1

What are the three main basic set methods?

Answer 1

• add()
• remove()
• clear()

Question 2

What is a set? Explain and demonstrate

Answer 2

• Structure that holds data in unsorted manner.
• Can hold mixed Data Types
• Parentheses {}

example_set = {"hallo", "genau", 8, "wie"} 

Question 3

Can you dublicate elements of the same Value in Sets?

Answer 3

• No
• It will not produce error, but will not be added

Question 4

How to make sets and other iterables immutable? Explain and demostrate

Answer 4

• By creating a frozen set
• There will not be any changes allowed
• Use () around the iterable

my_frozen_set = frozenset({1, 95, "Frozen")}

Question 5

Whats the difference between sets and lists?

Answer 5

• Lists allow to duplicate Elements within lists
• Lists are orderer

Question 6

Demonstrate how a list and a set are created

Answer 6

example_list = ["Hallo", 2, "!"]
example_set = {"Hallo", 2, "!"]

Question 7

Name 5 Methods you can use on Lists

Answer 7

append()
insert()
remove()
clear()
count()

Question 8

Which method does not work on lists and why? Also name alternatives.

Answer 8

add()

• Lists are ordered

Alternatives:
~~~
append() # adds to back
insert() # adds at specified index
~~~

Question 9

Why do we have both, sets and lists?

Answer 9

• Sets are much more effective and faster of identifying items
• Lists much faster in looping through to view or manipulate items

Question 10

What is a tupil? Explain and demonstrate

Answer 10

• Behaves like list structure but is immutable
• Sequence of immutable objects

example_tuple = ("Hallo", 3, "!")

Question 11

What is a Dictionary? Explain and demonstrate

Answer 11

• Collections that are unordered and mutable
• Each value consists of key and value

my_dictionary = {"Hair color": "Brown", "Eye Color : "Hazel"}

Question 12

There are two ways of obtaining values of dictionary key. Demonstrate.

Answer 12

1. Name in []

my_dictionary["Eye color"]

2. get()

my_dictionary.get("Age")

Question 13

How do you open Files in python. Explain and Demonstrate.

Answer 13

1. Open file with open method
2. Specify filename
3. Specify fileoption

my_file = open("myfile.txt", "w")

Question 14

Which file options exist? Explain

Answer 14

x - “create”
* Creates new file, with specified filename

a - “append”
* If file not exists: Create new one
* If file exists, all will be appended

w - “write”
* Create new file
* Erase all contents

r - “read”
* Default

Question 15

Write: “First File, here we go” to my_file Demonstrate

Answer 15

my_file = open("myfile.txt", "w")
my_file.write("First File, here we go")
my_file.close()

Question 16

What is a filelock. Explain

Answer 16

Prevents two (or more) applications from writing to the same files at the same time.

Question 17

How to read the file myfile.txt? Demonstrate

Answer 17

Opening the file “myfile.txt!” in read mode

# Opening the file in read mode
my_file = open("myfile.txt!", "r")

Reading data from the file
data = my_file.read()

Printing the data
print(data)

Closing the file
my_file.close()

Question 17

I want to open and write to a file called “thatfile.txt”. If the file does not exist, I want to create it but if it does exist, I want to write at the end of the file, preserving what’s already in the file. How do I do that? Demonstrate

Answer 17

my_file = open("thatfile.txt", "a")
my_file.write("Your Data\n")
file.close()