Simple Lexer using regex in python

pythonSimpleRegexLexer.py

```
import re
from collections import namedtuple

Token = namedtuple('Token', ['type', 'value', 'line', 'column'])

class Lexer(object):
    _KEYWORDS = {
        'if':       'IF_CONDITION',
        'while':    'WHILE_LOOP',
        'def':      'FUNCTION_DEFINITION',
        'return':   'FUNCTION_RETURNS',
        'True':     'TRUE_STATE',
        }

    _TOKEN_PATTERNS = [
        ('NUMBER',      r'\d+(\.\d*)?'), # any number of subseqeunt digits and a period character for floats
        ('ASSIGN',      r'='), # the = character
        ('SYMBOL',      r'[+*\/\-():>]'), # any of the +*\/\-():> characters
        ('NEWLINE',     r'\n'), # new line character
        ('INDENT',      r'^[ \t]+'), # space or tab character at start of a line
        ('WHITESPACE',  r'[ \t]'), # the space and tab character
        ('COMMENT',     r'#[^\n]+'), # anything after the # mark until the end of the line
        ('STRING',      r'"[^"]+"'), # anything inside "" marks
        ('NAME',        r'[^=#+*\/\- \t\d\n():>]+'),
    ]
    _RE_TOKEN_PATTERN = '|'.join('(?P<%s>%s)' % pair for pair in _TOKEN_PATTERNS)
    _RE_GET_TOKEN = re.compile(_RE_TOKEN_PATTERN, flags=re.MULTILINE).match

    def __init__(self, text):
        self.line = 1
        self.position = 0
        self.lineStart = 0
        self.text = text
        self.textlength = len(text)

    def __iter__(self):
        return self

    def __next__(self):
        while True:
            token = self.getCurrentToken()
            if token.type == 'NEWLINE':
                self.lineStart = self.position
                self.line += 1
            elif token.type != "WHITESPACE":
                return token

    def getCurrentToken(self):
        if self.position >= self.textlength:
            raise StopIteration()
        matched = self._RE_GET_TOKEN(self.text, self.position)
        if matched is not None:
            tokenType = matched.lastgroup
            column = matched.start() - self.lineStart
            tokenValue = matched.group(tokenType)
            tokenType = self._KEYWORDS.get(tokenValue, tokenType)
            self.position = matched.end()
            return Token(tokenType, tokenValue, self.line, column)
        raise RuntimeError('Unexpected character %r on line %d' %(self.text[self.position], self.line))

if __name__ == '__main__':
    test = '''
    def testFunc(inputNum):
        while True:
            if inputNume > 10:
                return inputNum
    testString = "نوشته"
    '''
    l = Lexer(test)
    t = []
    for token in l:
        print(token)
```