Python Regex - Program to Accept String Starting with Vowel

Given a string, the task is to check whether it starts with a vowel (a, e, i, o, u -> uppercase or lowercase). For example:

Input: animal -> Accepted
Input: zebra -> Not Accepted

Let's explore different regex-based methods to perform this check in Python.

Using re.fullmatch()

fullmatch() checks whether the entire string follows the pattern. We simply enforce that the first character is a vowel, and allow anything after it.

import re
text = "Animal"

pattern = r"^[AEIOUaeiou].*"

if re.fullmatch(pattern, text):
    print("Accepted")
else:
    print("Not Accepted")

Accepted

Explanation:

• ^ ensures checking starts at the beginning
• [AEIOUaeiou] means the first letter must be a vowel
• .* lets any characters appear afterward

Using re.match() with ^ Anchor

match() always checks from the beginning, so it can directly test whether the string starts with a vowel.

import re
text = "animal"
pattern = r"^[AEIOUaeiou].*"

if re.match(pattern, text):
    print("Accepted")
else:
    print("Not Accepted")

Accepted

Using re.search() With Start Anchor

search() scans the whole string, but because the regex begins with ^, the match is only valid if the string starts with a vowel.

import re
text = "animal"
pattern = r"^[AEIOUaeiou]"

if re.search(pattern, text):
    print("Accepted")
else:
    print("Not Accepted")

Accepted

Using re.findall()

findall() returns all parts of the string that match the pattern. Here, our pattern checks only the first character, so if the string starts with a vowel, the returned list will contain that vowel.

import re
text = "animal"
first = re.findall(r"^[AEIOUaeiou]", text)

if first:
    print("Accepted")
else:
    print("Not Accepted")

Accepted