Add RegX support

[sameeerkashyap]

Add RegX instead of string comparisons for file extensions.

[Keerthana-Thiagaraj]

Interested. Please let me know further about the issue

[sameeerkashyap]

@Keerthana-Thiagaraj if You take a look at tool.py , I am making many comparisons on the file extensions like .jpg .jpeg or png.

It would be better if this was done using a regular expression.

such as

r^'pattern'