String Operations

Question 1

Pull out the first digit in a string

Answer 1

stringname[0]

Question 2

Pull out the nth digit of a string

Answer 2

stringname[n]

Question 3

Pull out the last digit of a string (using negative indexing)

Answer 3

stringname[-1]

Question 4

find the length of a string

Answer 4

len(stringname)

Question 5

slice the first three digits of a string

Answer 5

stringname[0:3]

Question 6

get every second letter of a string

Answer 6

stringname[::2]

Question 7

get every second letter of a string starting from the 4th letter to the 8th

Answer 7

stringname[3:8:2]

Question 8

What is

‘1’ + ‘2’

Answer 8

‘12’

Question 9

how would i replicate a string three times

Answer 9

3 * “string goes in here”

OR

3 * stringname

Question 10

how do i make a new line in a printed string

Answer 10

\n

Question 11

how to i add a tab in a printed string

Answer 11

\t

Question 12

how do i put a backslash in a printed string

Answer 12

put two \

OR

print(r”string goes \ in here”)

Question 13

where do you put an r for raw string

Answer 13

just before the first “ of the string

Question 14

what is the general format for operations?

Answer 14

variable.operation()

Question 15

convert stringname to uppercase letters

Answer 15

newstringname = stringname.upper()

Question 16

convert stringname to lowercase letters

Answer 16

newstringname = stringname.lower()

Question 17

turn all instances of “michael” into “janet” in stringname - NOT RegEx

Answer 17

stringname.replace(“Michael”, “Janet”)

Question 18

how do you link repeated commands

Answer 18

stringname.function().function().function()

Question 19

write a command to figure out at what index number “Jack” starts in the string “Michael Jackson”

Answer 19

name = “Michael Jackson”
name.find(‘Jack’)

Question 20

what is output in a find command if the substring cannot be located in the string

Answer 20

-1

Question 21

what is the import to import Regular Expressions

Answer 21

import re

Question 22

how do you check whether there is a match for something in regular expression

Answer 22

result = re.search(pattern, stringname)

returns as NoneType or re.Match

Question 23

what would you use to match any digit in RegEx

Answer 23

\d

Question 24

what would match any non-word character in RegEx

Answer 24

\W

Question 25

what would match any white space character in RegEx

Answer 25

\s

Question 26

in RegEx, what is used to locate all of the occurrences of a specified pattern in a string

Answer 26

matches=re.findall(pattern, stringname)

outputs each individual instance in a list

Question 27

in RegEx, how would you separate a string into a list each time there was a space

Answer 27

list = re.split(“\s”, stringname)

Question 28

In RegEx, how would you replace all instances of “Tom” with “Mary”

Answer 28

output = re.sub(“Tom”, “Mary”, stringname)

Question 29

stringname.replace(“Matthew”, “Mary) is similar to what command in RegEx

Answer 29

re.sub(“Matthew”, “Mary”, stringname)

Question 30

how is search in RegEx different from find

Answer 30

find returns the index value for that substring (ie returns 9 for “jack” in “michael jackson”)

search tells you whether or not there is a match for such thing, and then you can use match.group() to display the match