Simple console FlashCard using Leitner System

flashcard.py

#!/usr/bin/python3
from time import time
import sqlite3
from sys import argv
import sys, tty, termios
from textwrap import fill

filepath = "/home/can/.flashcard.sqlite"

def getch():
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    try:
        tty.setraw(sys.stdin.fileno())
        ch = sys.stdin.read(1)
    finally:
        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    return ch

def now():
    return int(time())

def dropTable(cursor, table):
    cursor.execute("DROP TABLE IF EXISTS '" + table + "'")

def createTable(cursor, table):
    cursor.execute("CREATE TABLE IF NOT EXISTS '" + table +
            "'(last_review INTEGER DEFAULT 0, num_completion INTEGER DEFAULT 0,"
            + " front TEXT PRIMARY KEY, back TEXT)")

def insert(cursor, table, front, back, replace=False):
    cursor.execute("INSERT OR " + ("REPLACE" if replace else "IGNORE")
            + " INTO '" + table + "'(front, back) VALUES(?, ?)", (front, back))

def delete(cursor, table, front):
    cursor.execute("DELETE FROM '" + table + "' WHERE front=?", (front,))

def update(cursor, table, front, last_review, num_completion):
    cursor.execute("UPDATE '" + table +
            "' SET last_review=?, num_completion=? WHERE front=?",
            (last_review, num_completion, front))

def selectForReview(cursor, table, now, review):
    cursor.execute("SELECT * FROM '" + table +
            "' WHERE last_review <= CASE num_completion " +
            " ".join(["WHEN " + str(i) + " THEN " + str(now-t)
                for i,t in enumerate(review)]) + " ELSE " +
                str(now-review[-1]) + " END")

def listTables(cursor):
    cursor.execute("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name")

def loop(cursor, table):
    ESCAPE = chr(27)
    SPACE = chr(32)
    C_BOLDBLACK = "\033[1m"
    C_BOLDRED = "\033[1;31m"
    C_BOLDGREEN = "\033[1;32m"
    C_GRAY = "\033[0;38;5;250m"
    C_CLEAN = "\033[0m"
    def keyAction(char):
        if c == ESCAPE:
            sys.exit(0)
        elif c == "x":
            delete(cursor, table, front)
        elif c == "q":
            update(cursor, table, front, now(), num+1)
        elif c == "w":
            update(cursor, table, front, 0, 0)
    seconds_in_a_day = 86400
    review = [d*seconds_in_a_day for d in
            (0,4,7,12,20,30,60,90,150,270,480,730,1460,2190,4015)]
    selectForReview(cursor, table, now(), review)
    cards = cursor.fetchall()
    lencards = " / "+str(len(cards))
    for i,card in enumerate(cards):
        front, back, num = card[2], card[3], card[1]
        print(str(i+1)+lencards + C_GRAY +"\nFRONT: " + C_CLEAN + C_BOLDBLACK + 
                fill(front, 60, subsequent_indent="       "))
        print(C_GRAY + "---any key - x:delete - Esc:quit---" + C_CLEAN)
        c = getch()     # any key
        if c in ("x", ESCAPE):
            keyAction(c)
        else:
            print(C_GRAY + "BACK : " + C_CLEAN + 
                    fill(back, 60, subsequent_indent="       "))
            print(C_GRAY + "---"+C_BOLDGREEN+"q"+C_GRAY+":correct - "+ 
                    C_BOLDRED+"w"+C_GRAY+":wrong - x:delete - Esc:quit---" + C_CLEAN)
            c = getch()
            while c not in ("q", "w", "x", ESCAPE): c = getch()
            keyAction(c)

conn = sqlite3.connect(filepath)
conn.isolation_level = None
cursor = conn.cursor()
argc = len(argv)
if argc > 1:
    first = argv[1]
    if argc == 2:
        listTables(cursor)
        if (first,) in cursor.fetchall():
            loop(cursor, first)
        else:
            print("Category does not exist")
    elif first == "insert" and argc == 5:
        createTable(cursor, argv[2])
        insert(cursor, argv[2], argv[3], argv[4])
    elif first == "replace" and argc == 5:
        createTable(cursor, argv[2])
        insert(cursor, argv[2], argv[3], argv[4], True)
    elif first == "delete" and argc == 4:
        delete(cursor, argv[2], argv[3])
    elif first == "remove-category" and argc == 3:
        dropTable(cursor, argv[2])
    else:
        print ("Wrong parameters")
else:
    listTables(cursor)
    for t in cursor:
        print(t[0])