#!/usr/bin/env python3.7

# 2.1序列概述
# edward = ['Edward Gumby', 42]
# john = ['John Smith', 50]
# database = [edward, john]
# print(database) # [['Edward Gumby', 42], ['John Smith', 50]]

# 2.2
## 索引
# greeting = 'Hello'
# print(greeting[0]) # H
# print(greeting[3]) # l
# fourth = input('Year: ')[3]
# print(fourth)