Keg Interpreter Rewritten.py

import sys
#import Parse, random
import math

#All built-in functions
LENGTH = "!"
DUPLICATE = ":"
POP = "_"
PRINT_CHR = ","
PRINT_INT = "."
INPUT = "?"
L_SHIFT = '"'
R_SHIFT = "'"
RANDOM = "~"
REVERSE = "^"
SWAP = "$"

DESCRIPTIONS = {
    LENGTH: "Push the length of the stack",
    DUPLICATE: "Duplicate the top of stack",
    POP: "Pop the top of stack",
    PRINT_CHR: "Print the top of stack, calling ord(top)",
    PRINT_INT: "Print the top of stack, as is",
    INPUT: "Get input from user",
    L_SHIFT: "Left shift stack",
    R_SHIFT: "Right shift stack",
    RANDOM: "Push a random number between -inf and inf",
    REVERSE: "Reverse the stack",
    SWAP: "Swap the top two items on stack"
}

#Unofficial built-in functions
#Note: Most of these are from Btup/A__/User:A, so go check out their
#repos/esolang account/code golf userpage and upvote their answers

IOTA = "ï"
DECREMENT = ";"
SINE = "Š"

DESCRIPTIONS[IOTA] = "Replaces the top of stack with all items from [top->0]"
DESCRIPTIONS[DECREMENT] = "Decrement the top of stack"
DESCRIPTIONS[SINE] = "sin(top)"

#'Keywords'

COMMENT = "#"
BRANCH = "|"
ESCAPE = "\\"
REGISTER = "&"
ECOM_STRING = "`"
FUNCTION = "@"