del var1[,var2[,var3[....,varN]]]
del var
del var_a, var_b

str = 'Hello World!'
 
print(str)           # 输出完整字符串
print(str[0])        # 输出字符串中的第一个字符
print(str[2:5])      # 输出字符串中第三个至第六个之间的字符串
print(str[2:])       # 输出从第三个字符开始的字符串
print(str * 2)       # 输出字符串两次
print(str + "TEST")  # 输出连接的字符串

list = [ 'run', 786 , 2.23, 'john', 70.2 ]
tiny = [123, 'john']
 
print(list)               # 输出完整列表
print(list[0])            # 输出列表的第一个元素
print(list[1:3])          # 输出第二个至第三个元素 
print(list[2:])           # 输出从第三个开始至列表末尾的所有元素
print(tiny * 2)           # 输出列表两次
print(list + tiny)        # 打印组合的列表

'''
['run', 786, 2.23, 'john', 70.2]
run
[786, 2.23]
[2.23, 'john', 70.2]
[123, 'john', 123, 'john']
['run', 786, 2.23, 'john', 70.2, 123, 'john']
'''

tuple = ( 'runoob', 786 , 2.23, 'john', 70.2 )
tinytuple = (123, 'john')
 
print(tuple)               # 输出完整元组
print(tuple[0])            # 输出元组的第一个元素
print(tuple[1:3])          # 输出第二个至第四个（不包含）的元素 
print(tuple[2:])           # 输出从第三个开始至列表末尾的所有元素
print(tinytuple * 2)       # 输出元组两次
print(tuple + tinytuple)   # 打印组合的元组

tuple[2] = 1000      # 元组中是非法应用
list[2] = 1000       # 列表中是合法应用

dict = {}
dict['one'] = "This is one"
dict[2] = "This is two"
 
tinydict = {'name': 'runoob', 'code': 6734, 'dept': 'sales'}
 
 
print(dict['one'])          # 输出键为'one' 的值
print(dict[2])              # 输出键为 2 的值
print(tinydict)             # 输出完整的字典
print(tinydict.keys())      # 输出所有键
print(tinydict.values())    # 输出所有值

a = 10, b = 20
list = [1, 2, 3, 4, 5, 10]

if (a in list):
    print(a)
if (b not in list):
    print(-b)

a = b = 10
c = 20
print(a is b)
print(b is c)

if 判断语句1:
    执行语句1....
elif 判断语句2:
    执行语句2...
else:
    执行语句3

a = 10
while a < 100:
    print(a)
    a += 1

while a < 200:
    a *= 2
else:
    print("end")

for c in "Python":
    print(c)

a = 2
list = [1, "python", 2]
for i in range(len(list)):
    print(list[i])

for i in range(10, 20):   # 等价于 for (int i = 10; i < 20; i++)
    print(i)

for i in range(10, 20):   # 等价于 for (int i = 10; i <= 20; i++)
    if i % 10 == 0:
        pass
    else:
        print(i)

def output(str):
    print(str)
    return

output("你好")