Data Types - String

Question 1

An easy method to change a string to all capitals

Answer 1

“Hello”.upper()

(= “HELLO”)

Question 2

An easy method to change a string to all lower case

Answer 2

“Hello”.lower()

(= “hello”)

Question 3

An easy method to capitalize the first character of each word in a string

Answer 3

“hello world”.title()

(= “Hello World”)

Question 4

Join the below 2 strings into a sentence using String Concatenation,

“Hello”
“World”

Answer 4

“Hello” + “ “ + “World”

Question 5

Join the below 2 strings into a sentence using f-strings,

“Hello”
name = “Richard”

Answer 5

f”Hello {name}”

Question 6

Give 2 efficient methods of finding the starting index number of the sub-string “love” in “I love Python”

Answer 6

“I love Python”.index(“love”)
&
“I love Python”.find(“love”)

Question 7

For finding the starting index number of a sub-string in a string, what is the difference between the following 2 methods,

.find()
.index()

Answer 7

.index() - returns an error
&
.find() - returns -1

Question 8

A method to find how many times “a” appears in “apples and pears”

Answer 8

“apples and pears”.count(“a”)

Question 9

Write a single-line truthy/falsy script that will check if the sub-string “love” is within the string “I love Python”, and if so, returns True

Answer 9

Return “love” in “I love Python”

Question 10

Write a single-line truthy/falsy script that will check if the sub-string “love” is within the string “I love Python”, and if so, evaluate as False

(It should merely evaluate as False, not return False)

Answer 10

“love” not in “I love Python”
or
not “love” in “I love Python”

Question 11

A method to replace “hate” with “love” in the string below”

“I hate Python”

Answer 11

txt = “I hate python”.replace(“hate”, “love”)

Remember to store it in a variable since strings are immutable

Question 12

A method that changes;
“apple,banana,orange”
to
[“apple”, “banana”, “orange”]

Answer 12

“apple,banana,orange”.split(“,”)

Question 13

A method that changes;
[“2024”, “12”, “31”]
to
“2024-12-31”

Answer 13

”-“.join([“2024”, “12”, “31”])

Question 14

A method that changes;
“ABC”
to
“A/B/C”

Answer 14

”/”.join(“ABC”)

Question 15

A method that changes
“ hello world ! “
to
“hello world !”

Answer 15

” hello world ! “.strip()

(removes whitespace from the beginning and the end of a string - but not from the middle)

Question 16

A method that changes
“ hello world ! “
to
“hello world ! “

Answer 16

” hello world ! “.lstrip()

(removes whitespace from the left of a string - but not from the right or the middle)

Question 17

A method that changes
“ hello world ! “
to
“ hello world !”

Answer 17

” hello world ! “.rstrip()

(removes whitespace from the right of a string - but not from the left or the middle)

Question 18

Print “Pyt” from “Python”

Answer 18

print(“Python”[ :3])

Question 19

Print “tho” from “Python”

Answer 19

print(“Python”[2:5])

Question 20

Print “hon” from “Python”

Give two methods of slicing

Answer 20

1)
print(“Python”[3: ])

2)
print(“Python”[-3: ])

The “:” is very important! Without it, the result would be “h” !!

Question 21

Print “Pto” from “Python”

Answer 21

print(“Python”[ : :2])

Question 22

Print “yhn” from “Python”

Answer 22

print(“Python”[1: :2])

Question 23

Print “nhy” from “Python”

Answer 23

print(“Python”[ : :-2])

or

print(“Python”[-1: :-2])

Question 24

Print “otP” from “Python”

Answer 24

print(“Python”[-2: :-2])

Question 25

What's the difference between the below, print("Python"[ : :-2]) vs print("Python"[-1: :-2])

Answer 25

Nothing - they give the same result

Question 26

Print "n" from "Python"

Answer 26

print("Python"[-1])

Question 27

print("*" * 3) What will the terminal output be

Answer 27

Terminal output = ***

Question 28

a = '1 2 3' a.split() print(a) What will the above print and why

Answer 28

It will print, 1 2 3 (I.e., unaltered), rather than, ['1', '2', '3'] .split() always wants to return a NEW list — it does not modify the original string "in place". To use the result, it should be assigned to a variable like this: a = a.split() ## Footnote 1) .split() is a method that only operates on strings. Remember, Strings are immutable, so they can never be modified "in place".

Question 29

var = "abc".split("") What will the above return Why

Answer 29

ValueError Although .split() requires a string as a separator, it must be a non-empty string that says where to split the string into a list

Question 30

Turn "abc" into ["a", "b", "c"]

Answer 30

list("abc")

Question 31

Turn "16 1 246 7" into ["16", "1", "246", "7"]

Answer 31

var = "16 1 246 7".split( ) ## Footnote An empty .split() splits by whitespace - same as .split(" ") Note that, since a string is immutable, the result should be stored in a variable to work

Question 32

Turn "a,b,c" into ["a", "b", "c"]

Answer 32

var = "a,b,c".split(",") | An empty .split() splits by whitespace - same as .split(" ") ## Footnote Note that, since a string is immutable, the result should be stored in a variable to work

Question 33

Change, "hELLO wORLD" To, "Hello World"

Answer 33

word = "hELLO wORLD".swapcase()

Question 34

for char in txt: print(txt[char]) What does the above print

Answer 34

TypeError This treats "char" like it's an index, but it actually refers to an item (in this case a character in "txt"). If you want to print the Item/character, it should be typed as below, for char in txt: print(char)

Question 35

Give two methods to check if a character is uppercase or lowercase

Answer 35

.isupper() .islower() | These will return True or False

Question 36

Print "P" from "Python"

Answer 36

print("Python"[0]) ## Footnote print("Python"[ ]) returns SyntaxError as there is no default index number when trying to slice with empty square brackets

Question 37

"short sentence".count("a","e","i","o","u") What will the above return if printed

Answer 37

TypeError the ".count()" method can only take one parameter at a time

Question 38

def get_count(sentence): total_count = 0 total_count += sentence.count("a") total_count += sentence.count("e") total_count += sentence.count("i") total_count += sentence.count("o") total_count += sentence.count("u") return total_count Give a shorter way of writing the above

Answer 38

def get_count(sentence): total_count = 0 for char in "aeiou": total_count += sentence.count(char) return total_count

Question 39

"Hello World !" Loop through this String checking if **each** character is alphabetical & if so, **print True for each individual character**

Answer 39

for char in "Hello World !": if char.isalpha(): print(True)

Question 40

num = int(2) Print the above int as the String "002" by using **f-strings** and **padding**

Answer 40

num = int(2) print(f"{num:03}") ## Footnote In ":03" the "3" is the total number of digits required, and "0" is the required leading numbers

Question 41

.title() vs .capitalize()

Answer 41

.capitalize() capitalizes the first character in a String .title() capitalizes the first character of **every** word in a String

Question 42

nums = "part one" "part two" "part three" What does print(nums) print

Answer 42

An error To avoid this error, you must use "\" as follows; nums = "part one"\ "part two"\ "part three" this prints "part onepart twopart three"

Question 43

def solution(string, ending): Complete the function above so that it returns true if the first argument "string" ends with the 2nd argument "ending". E.g., string, ending = "abc", "bc" # True string, ending = "abc", "d" # False

Answer 43

def solution(string, ending): return string.endswith(ending)

Question 44

What is the .endswith() method, and how do you use it?

Answer 44

.endswith() checks if a string ends with the given suffix. It returns True if it does, otherwise False. E.g., "photo.jpeg".endswith(".jpg") # True

Question 45

How do you check if a string ends with any of multiple suffixes?

Answer 45

Pass a tuple of suffixes to .endswith() E.g., filename = "photo.jpeg" filename.endswith((".png", ".jpg", ".jpeg")) # True

Question 46

text = "python_programming" Using .endswith(), check if "python" in "text" ends with "hon"

Answer 46

text.endswith("hon", 0, 6) # True ## Footnote Syntax: string.endswith(suffix, start, end)