How to check if a sentence start with a given word in python ?


Python provides several ways to check if a given sentence starts with a certain word. The most straightforward approach is using the startswith() method. Examples:

Using python built-in function startswith()

This function takes in two arguments, a string and an optional flag that checks for case sensitivity, which defaults to False. If the sentence begins with the specified word, true will be returned; otherwise, false will be returned. For example, to check if a sentence starts with the word "Hello", we can use the following code:

sentence = "Hello How are you today ?"

sentence.startswith('Hello')

output of the above code is

True

While

sentence.startswith('Hi')

returns

False

Using startswith() with a if statement

if sentence.startswith('Hello'):

    print("Sentence Starts With 'Hello'")

returns

"Sentence Starts With 'Hello'

Using regular expressions

Alternatively, we can use regular expressions to match the start of a sentence. To do this, we can use the re.match() function which takes in two arguments, a regex pattern and the string to be matched. For example:

    import re

    sentence = "Hello How are you today ?"

    if re.match('Hello', sentence):

        print("Sentence Starts With 'Hello'")

output

Sentence Starts With 'Hello'

Note that it is case sensitive

if re.match('hello', sentence):

print("Sentence Starts With 'hello'")

returns nothing

Using find

Finally, we can also use the find() method with a start parameter to look for the first occurrence of a word in the sentence. For example:

    sentence = "Hello How are you today ?"

    if sentence.find('Hello', 0) == 0:

        print("Sentence Starts With 'Hello'")

output

    Sentence Starts With 'Hello'

References

Links Site
startswith() docs.python.org
regular expressions docs.python.org
find() docs.python.org