Regular Expression, or RegEx, is a sequence of charaters that form a search pattern.
Regular Expression can be used to check if a string contains the specified search pattern. RegEx is like a code or a group of symbols used to filter through strings and this brief tutorial will not even cover the depth of it, but it will serve as an introduction to the concept.
import re
txt = "The rain in Spain"
x = re.search("^The,*Spain$", txt)
functions findall - returns a list containing all matches search - returns a [match object] if there is a match in the string split - returns a list where the string has been slipt at each match sub - replaces one or many matches with a string
metacharaters charaters with special meaning [] - a set of charaters - “[a-m]” \ - Signals a special sequence - “\d” . - any charater (except newline charater) - “he..o” ^ - Starts with - “^hello” $ - Ends with - “world$”
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- Zero or more occurrences “aix*”
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- one or more occurencecs “aix+” {} - Exactly the specified number of occurrences “al{2}” | - Either or - “falls|stays” () - Capture and group
I am given a blig block of text using bs4.soup.all_text() and want to filter for only the part of the page I want. For this, lets try a couple expressions using Regular Expression.
import re
import bs4 as soup
song = 'https://www.azlyrics.com/lyrics/marsvolta/eunuchprovocatuer.html'
song_page = requests.get(song)
soup = BeautifulSoup(song_page.content, 'html.parser'
all_txt = soup.get_text()
lyrics = []
soup = with open('')
txt = soup.all_text()
for row in txt:
Counter = 0
if (row = re.search("^[Lyrics] "$):
for row == "/n" counter += 1
when counter <= 4
lyrics.append(row)
if counter <=8
break
^this is a mess of pseudocode that might loosely represent my thought process.
what is a match object? a match object is an object containing information about the search and the result.
match objects have properties. .span() - returns a tuple containing the start and end positions of a match .string - returns the string passed into the function .group() - returns the part of the string where there was a match