parser.py

import re


# This class will provide useful utilities for parsing inputting strings, such as removing the need to write np.cos.
class TextParse:

    def __init__(self, text):
        self.text = text
        self.keywords = ["cos", "sin", "exp", "log", "tan"]


    # Some explanation of the functionning of these regex patterns
    #
    # r is necessary because if not, the string wont be in raw mode and \b will be interperted
    # as a backspace and not a "word boundary" for regex
    #
    # \b means word boundary, example \bcat\b matches "here is a cat" but not "catalog"
    #
    # \d matches any digit
    #
    # | is concatenation in regex
    #
    # \1, \2, ect, refers to the content matched in the first capturing group
    # the part of the pattern in the first set of parentheses. It is useful to saveguard the context.
    def parse(self):

        self.text = re.sub(r'\b(' + '|'.join(map(re.escape, self.keywords)) + r')\b', r'np.\1', self.text)
        self.text = re.sub(r'(\d)x', r'\1*x', self.text)

        return self.text