Jul 13, 2025
diff --git a/string_utils/validation.py b/string_utils/validation.py
    return valid


 from typing import Any
 import re
 from .strings import is_full_string   # 同仓库内部函数

 EMAIL_RE = re.compile(r'^[^@]+@[^@]+\.[^@]+$')
 ESCAPED_AT_SIGN = re.compile(r'(?<!\\)@')

 def is_email(input_string: Any) -> bool:
    """
    Check if a string is a valid email.
    :type input_string: str
    :return: True if email, false otherwise.
    """
    # first simple "pre check": it must be a non empty string with max len 320 and cannot start with a dot
    # 1. 空字符串直接返回 False（本次新增）
    if input_string == "":
        return False

    # 2. 基础预检
    if not is_full_string(input_string) or len(input_string) > 320 or input_string.startswith('.'):
        return False

    try:
        # we expect 2 tokens, one before "@" and one after, otherwise we have an exception and the email is not valid
        head, tail = input_string.split('@')

        # head's size must be <= 64, tail <= 255, head must not start with a dot or contain multiple consecutive dots
        if len(head) > 64 or len(tail) > 255 or head.endswith('.') or ('..' in head):
            return False

        # removes escaped spaces, so that later on the test regex will accept the string
        head = head.replace('\\ ', '')
        if head.startswith('"') and head.endswith('"'):
            head = head.replace(' ', '')[1:-1]

        return EMAIL_RE.match(head + '@' + tail) is not None

    except ValueError:
        # borderline case in which we have multiple "@" signs but the head part is correctly escaped
        if ESCAPED_AT_SIGN.search(input_string) is not None:
            # replace "@" with "a" in the head
            return is_email(ESCAPED_AT_SIGN.sub('a', input_string))

        return False
Original file line number	Diff line number	Diff line change
Expand Up		@@ -201,6 +201,13 @@ def is_url(input_string: Any, allowed_schemes: Optional[List[str]] = None) -> bo
		return valid


		from typing import Any
		import re
		from .strings import is_full_string # 同仓库内部函数

		EMAIL_RE = re.compile(r'^[^@]+@[^@]+\.[^@]+$')
		ESCAPED_AT_SIGN = re.compile(r'(?<!\\)@')

		def is_email(input_string: Any) -> bool:
		"""
		Check if a string is a valid email.
Expand All		@@ -216,31 +223,29 @@ def is_email(input_string: Any) -> bool:
		:type input_string: str
		:return: True if email, false otherwise.
		"""
		# first simple "pre check": it must be a non empty string with max len 320 and cannot start with a dot
		# 1. 空字符串直接返回 False（本次新增）
		if input_string == "":
		return False

		# 2. 基础预检
		if not is_full_string(input_string) or len(input_string) > 320 or input_string.startswith('.'):
		return False

		try:
		# we expect 2 tokens, one before "@" and one after, otherwise we have an exception and the email is not valid
		head, tail = input_string.split('@')

		# head's size must be <= 64, tail <= 255, head must not start with a dot or contain multiple consecutive dots
		if len(head) > 64 or len(tail) > 255 or head.endswith('.') or ('..' in head):
		return False

		# removes escaped spaces, so that later on the test regex will accept the string
		head = head.replace('\\ ', '')
		if head.startswith('"') and head.endswith('"'):
		head = head.replace(' ', '')[1:-1]

		return EMAIL_RE.match(head + '@' + tail) is not None

		except ValueError:
		# borderline case in which we have multiple "@" signs but the head part is correctly escaped
		if ESCAPED_AT_SIGN.search(input_string) is not None:
		# replace "@" with "a" in the head
		return is_email(ESCAPED_AT_SIGN.sub('a', input_string))

		return False


Expand Down