Unit 5: Strings

Question 1

What is the purpose of string slicing ?

Answer 1

read more than one character at a time. Multiple consecutive characters can be read using slice notation.

Question 2

Slice notation syntax

Answer 2

my_str[start:end]

Question 3

Determines how much to increment the index after reading each element

Answer 3

Stride

Question 4

Stride syntax in slice notation

Answer 4

my_str[start:end:stride]

Question 5

format specification that defines the minimum number of characters that must be inserted into the string. If the replacement value is smaller in size than the given field width, then the string is padded with space characters.

Answer 5

Field width

Question 6

Field width syntax

Answer 6

{name:16}

Question 7

character that determines how a value should be aligned within the width of the field.

Answer 7

Alignment character

Question 8

alignment character format

Answer 8

{name:>16}

Question 9

is used to pad a replacement field when the inserted string is smaller than the field width. The default character is an empty space ‘ ‘

Answer 9

Fill character

Question 10

fill character syntax

Answer 10

{name:0>16}

Question 11

floating point precision

Answer 11

format specification indicates how many digits should be included in the output of floating types.

Question 12

floating point precision syntax

Answer 12

{name:0>16.2f}
{variable_name:.2f}

Question 13

replace(old, new)

Answer 13

Returns a copy of the string with all occurrences of the substring old replaced by the string new. The old and new arguments may be string variables or string literals.

Question 14

replace(old, new, count)

Answer 14

Same as above, except replace(old, new, count) only replaces the first count occurrences of old.

Question 15

find(x)

Answer 15

find(x) – Returns the index of the first occurrence of item x in the string, otherwise, find(x) returns -1. x may be a string variable or string literal

Question 16

find(x, start)

Answer 16

Same as find(x), but begins the search at index start

Question 17

find(x, start, end)

Answer 17

Same as find(x, start), but stops the search at index end - 1

Question 18

rfind(x)

Answer 18

Same as find(x) but searches the string in reverse, returning the last occurrence in the string.

Question 19

count(x)

Answer 19

Returns the number of times x occurs in the string

Question 20

syntax for positional string methods

Answer 20

my_str.method()

Question 21

Methods to check a string value that returns a True or False Boolean value:

Answer 21

isalnum() – Returns True if all characters in the string are lowercase or uppercase letters, or the numbers 0-9.
isdigit() – Returns True if all characters are the numbers 0-9.
islower() – Returns True if all cased characters are lowercase letters.
isupper() – Returns True if all cased characters are uppercase letters.
isspace() – Returns True if all characters are whitespace.
startswith(x) – Returns True if the string starts with x.
endswith(x) – Returns True if the string ends with x.

Question 22

Methods to create new strings

Answer 22

capitalize() – Returns a copy of the string with the first character capitalized and the rest lowercased.
lower() – Returns a copy of the string with all characters lowercased.
upper() – Returns a copy of the string with all characters uppercased.
strip() – Returns a copy of the string with leading and trailing whitespace removed.
title() – Returns a copy of the string as a title, with first letters of words capitalized.

Question 22

Methods to create new strings

Answer 22

capitalize() – Returns a copy of the string with the first character capitalized and the rest lowercased.
lower() – Returns a copy of the string with all characters lowercased.
upper() – Returns a copy of the string with all characters uppercased.
strip() – Returns a copy of the string with leading and trailing whitespace removed.
title() – Returns a copy of the string as a title, with first letters of words capitalized.

Question 23

split() method

Answer 23

The string method split() splits a string into a list of tokens. Each token is a substring that forms a part of a larger string. A separator is a character or sequence of characters that indicates where to split the string into tokens

Question 24

split method syntax

Answer 24

my_str.split(‘seperator’)

Question 25

join() method

Answer 25

string method performs the inverse operation of split() by joining a list of strings together to create a single string.

Question 26

join() method syntax

Answer 26

my_str = ‘seperator’.join(my_token)