num = 10
num = bin(num)
print(num)

num = "0b1010"
num = int(num, 2)
print(num)

string = "a"
print(ord(string))

code = 97
print(chr(code))

arr = [1, 3, 2, 6, 4, 5]
arr.sort()  # 因為 sort() 會回傳 None 所以不能直接用重新賦值的方式
print(arr)

arr = [1, 3, 2, 6, 4, 5]
arr = sorted(arr)
print(arr)

arr = [1, 3, 2, 6, 4, 5]
arr = sorted(arr, reverse=True)
print(arr)

hashmap = {"Apple": 10, "Banana": 100, "Cake": 0}
hashmap = sorted(hashmap.items(), key=lambda a: (a[1], a[0]))
print(hashmap)

num = bin(10)
print(num[2:])  # 把 0b 開頭刪去

string = "hello world!"
print(string[::-1])

def double(num):
    return num * num

arr = [1, 2, 3, 4, 5]
arr = list(map(double, arr))
print(arr)