Source code for helper_functions

#!/usr/bin/env python

import os
import datetime
import subprocess

def cls():
    """cls() will clear the screen.  Works in linux or windows"""
    os.system('cls' if os.name=='nt' else 'clear')

def menu(options, title = "Your options are:", prompt = "Select an option by number: "):
    """The menu function numbers and presents a set of options to the user, expects the user to select the number that equates to the option to be selected and returns that option.

    :param options: Set of options to be presented to the user, defaults to (no default option)

    :type options: tuple of str

    :param title: The title that will appear at the top of the set of options, defaults to "Your options are:"

    :type title: str

    :param prompt: The text that will appear at the bottom of the set of options prompting the user to make a selection, defaults to "Select an option by number: "

    :type prompt: str
    
    :return: option selected by user

    :rtype: str"""


    __choice = ""
    __choice_no = 100
    while not(__choice in options):
        __nameList = []
        print("\n" + underline(title))
        for __index, __item in enumerate(options, start=1):
            __nameList.append(__item)
            print(str(__index) + ": " + __item)
        try:
            while not(__choice_no <= len(options) and __choice_no > 0):
                __choice_no = int(input("\n" + prompt))
            __choice = __nameList[(__choice_no - 1)]
        except:
            print("You must enter a number.  Try again!")
    return __choice


def underline(text):
    """Underlines text (with equals signs).    

    :param text: The text to be underlined

    :type text: str    
    
    :return: Single string made up of the supplied text, a carriage return and the appropriate number of equals signs.   

    :rtype: str""" 

    __underline = ""
    __counter = 0
    while __counter < len(text):
        __underline = __underline + "="
        __counter += 1
    text = text + "\n" + __underline
    return text
    
def datetag():
    x = datetime.datetime.now()
    y = str(x.strftime("%Y"))
    m = str(x.strftime("%m"))
    d = str(x.strftime("%d"))
    tag = y + m + d
    return tag

def mysql_backup(sdb, shost, username, password):
    tag = datetag()
    output_file = "../../34-MySQL_Databases/00-SQL_backups/{}-backup_{}.sql".format(sdb, tag)
    try:
        subprocess.check_call(
            "mysqldump -u %s -p%s -h %s -e --opt --max_allowed_packet=512M -c %s > %s" % (username, password, shost, sdb, output_file),
            shell=True)
    except subprocess.CalledProcessError as e:
        print("Error: mysqldump ended with status %s, check DB credentials" % e.returncode)
        exit(1)

def mainloop():
    """Just a test routine that will present the user with a list of the days of the week for selection IF the module is run in its own right rather than being called from another module."""
    cls()
    example_list = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday", "Quit"]
    state = "Confused"
    while state != "Quit":
        state = menu(example_list)
        print("\nYou chose " + state + "\n")
    
if __name__ == "__main__":
    mainloop()