A hashtag is a keyword or phrase preceded by the hash symbol (#), written within a post or comment to highlight it and facilitate a search for it. Some examples are: #like, #gfg, #selfie
We are provided with a string containing hashtags, we have to extract these hashtags into a list and print them.
Examples:
Input : Lazyroar is a wonderful #website for #ComputerScience
Output : website , ComputerScience
Input : This day is beautiful! #instagood #photooftheday #cute
Output : instagood, photooftheday, cute
Method 1:
- Split the text into words using the split() method.
- For every word check if the first character is a hash symbol(#) or not.
- If yes then add the word to the list of hashtags without the hash symbol.
- Print the list of hashtags.
Python3
# function to print all the hashtags in a textdef extract_hashtags(text): # initializing hashtag_list variable hashtag_list = [] # splitting the text into words for word in text.split(): # checking the first character of every word if word[0] == '#': # adding the word to the hashtag_list hashtag_list.append(word[1:]) # printing the hashtag_list print("The hashtags in \"" + text + "\" are :") for hashtag in hashtag_list: print(hashtag)if __name__ == "__main__": text1 = "Lazyroar is a wonderful #website for #ComputerScience" text2 = "This day is beautiful ! #instagood #photooftheday #cute" extract_hashtags(text1) extract_hashtags(text2) |
The hashtags in "Lazyroar is a wonderful #website for #ComputerScience" are : website ComputerScience The hashtags in "This day is beautiful ! #instagood #photooftheday #cute" are : instagood photooftheday cute
Time complexity: O(n), where n is the number of words in the text.
Auxiliary space: O(n), where n is the number of hashtags in the text.
Method 2 : Using regular expressions.
Python3
# import the regex moduleimport re# function to print all the hashtags in a textdef extract_hashtags(text): # the regular expression regex = "#(\w+)" # extracting the hashtags hashtag_list = re.findall(regex, text) # printing the hashtag_list print("The hashtags in \"" + text + "\" are :") for hashtag in hashtag_list: print(hashtag)if __name__ == "__main__": text1 = "Lazyroar is a wonderful #website for #ComputerScience" text2 = "This day is beautiful ! #instagood #photooftheday #cute" extract_hashtags(text1) extract_hashtags(text2) |
The hashtags in "Lazyroar is a wonderful #website for #ComputerScience" are : website ComputerScience The hashtags in "This day is beautiful ! #instagood #photooftheday #cute" are : instagood photooftheday cute
Method 3 : Using startswith() and replace()
Python3
# program to print all the hashtags in a texttext1 = "Lazyroar is a wonderful #website for #ComputerScience"textList = text1.split()for i in textList: if(i.startswith("#")): x = i.replace("#", '') print(x) |
website ComputerScience
Method 4 : Using replace()
Python3
# program to print all the hashtags in a texttext1 = "Lazyroar is a wonderful #website for #ComputerScience"textList = text1.split()for i in textList: if(i[0] == "#"): x = i.replace("#", '') print(x) |
website ComputerScience
Method 5 : Using find() and replace() methods
Python3
# program to print all the hashtags in a texttext1 = "Lazyroar is a wonderful #website for #ComputerScience"textList = text1.split()for i in textList: if(i.find("#") == 0): x = i.replace("#", '') print(x) |
website ComputerScience
