regex

Question 1

\w

Answer 1

alphanumeric values
r”[\w]ears” === __ears

Question 2

”^”

Answer 2

matches the position at the beginning of string (unless used for negation “[ˆ]”)

Question 3

”$”

Answer 3

matches the position at the end of string character.

Question 4

”?”

Answer 4

match preceding literal or sub- expression 0 or 1 times.

Question 5

”+”

Answer 5

match preceding literal or sub- expression one or more times.

Question 6

“*”

Answer 6

match preceding literal or sub- expression zero or more times

Question 7

”.”

Answer 7

match any character except new line

Question 8

”[ ]”

Answer 8

match preceding literal or sub- expression zero or more times

Question 9

”( )”

Answer 9

used to create a sub-expression

Question 10

” \d “

Answer 10

match any digit character. “\D” is the complement

Question 11

” \w “

Answer 11

match any word character (letters, dig- its, underscore). “\W” is the comple- ment.

Question 12

“\s”

Answer 12

match any whitespace character in- cluding tabs and newlines. \S is the complement.

Question 13

“*?”

Answer 13

Non-greedy version of *. Not fully discussed in class

Question 14

“\b”

Answer 14

match boundary between words. Not discussed in class.

Question 15

”+?”

Answer 15

Non-greedy version of +. Not discussed in class.

Question 16

“{m+n}”

Answer 16

The preceding element or subex- pression must occur between m and n times, inclusive

Question 17

re.split(pattern, string)

Answer 17

split
the string at substrings that match
the pattern. Returns a list.

Question 18

re.sub(pattern, replace, string)

Answer 18

apply the pattern to string replac-
ing matching substrings with replace.

Returns a string.

Question 19

re.findall(pattern, string)

Answer 19

Returns a list of all matches for the given
pattern in the string.