Suppose we have an email address as string. We have to check whether this is valid or not based on the following conditions −
The format must be [email protected] format
Username can only contain upper and lowercase letters, numbers, dashes and underscores
Company name can only contain upper and lowercase letters and numbers
Domain can only contain upper and lowercase letters
Maximum length of the extension is 3.
We can use regular expression to validate the mail addresses. Regular expressions can be used by importing re library. To match a pattern we shall use match() function under re library.
So, if the input is like s = "[email protected]", then the output will be True
To solve this, we will follow these steps −
- pat := "starting with [a-zA-Z0-9-_] then @ then company name with [a-zA-Z0-9] then separated by dot and domain with [a-z] whose length is 1 to 3 and this is present at end"
- if pat matches with s, then
- return True
- otherwise return False
Example
Let us see the following implementation to get better understanding
import re def solve(s): pat = "^[a-zA-Z0-9-_]+@[a-zA-Z0-9]+\.[a-z]{1,3}$" if re.match(pat,s): return True return False s = "[email protected]" print(solve(s))
Input
"[email protected]"
Output
True