Guetzli wrapper for Python

guetzli.py

import os
import sys


class GuentzliWrapper:
    """ This Class is wrapper for the guentzli, google develped.

    You can encode multiple (jpeg || png) file via guentzli on CLI.
    ( Tested: Python 3.6, 2.7.13, pypy 5.7.0)

    Put this file anywhere. And put this file of path to .bashrc or .zshrc
    and then ...

    # to .bashrc or .zshrc * any command name you want
    alias myguent='python /YOUR/PATH/guetzli.py '

    then souce ~/.bashrc OR ~/.zshrc

    # usage
    $ myguent myimg.jpeg

    or multiple images..
    $ myguent myimg1.jpeg myimg2.jpeg myimg3.jpeg

    """

    def __init__(self):
        self.dir = os.getcwd() + '/'
        self.inputs = sys.argv

        self.color = {
            'green': '\033[92m',
            'red': '\033[91m',
            'blue': '\033[94m',
            'end': '\033[0m'
        }

        del self.inputs[0]  # remove self-file-name

        pass

    def _check_File_Type(self):

        for x in self.inputs:
            if not x.endswith((".jpeg", ".jpg", ".png")):
                print(self.color["red"] + x +
                      ' is invalid extention' + self.color["end"])
                return False
        pass

    def _check_File_Exists(self):

        try:
            if len(self.inputs) is 0:
                raise Exception("Error: none-argument")

            if self._check_File_Type() is False:
                raise Exception("Error: invalid file-type")

            array = list()

            for x in self.inputs:

                if os.path.exists(self.dir + x) is False:
                    raise Exception("File: " + self.dir + x + " is not exist")
                else:
                    array.append(x)
            pass

            return list(set(array)) # remove element if contains duplicated

        except Exception as e:
            print(self.color["red"] + e + self.color["end"])
            return sys.exit()

            pass

        pass

    def _percentage(self, before, after):
        return round(100 - (float(after) / before * 100), 2)
        pass

    def execute(self):

        for x in self._check_File_Exists():

            before = os.path.getsize(x)

            print("PROGRESS: " + x)
            # execute guetzli command
            os.system("guetzli {0} {1}".format(
                self.dir + x,
                self.dir + x.replace('.png', '.jpeg'))
            )

            if x.endswith('.png') is True:
                # if file is .png
                print(self.color["green"] + "Created JPEG image : {0} \033[0m \n"
                      .format(x.replace('.png', '.jpeg')))
            else:
                after = os.path.getsize(x)
                print(self.color["green"] + "{0} byte -> {1} byte ( {2}% reduced ) \033[0m \n"
                      .format(before, after, self._percentage(before, after)))


        print(self.color["blue"] + "Completed !!" + self.color['end'])

        pass

if __name__ == "__main__":
    x = GuentzliWrapper()
    x.execute()