python基本语法001

print("Hello World")

s = "tom"
i = "22"
print("name:" + s + ",age:" + i)


ss = "tom"
ii = 22
print("name:" + ss + ",age:" +str(ii) )

print("name:%s,age:%d" %(ss,ii))

print("name:{s},age:{i}".format(s=ss,i=ii))


# 字符串，不分单引号还是双引号，不能交叉使用
a = 'aaa'
b = "aaa"
c = "he says:'hello'"
d = 'he says:"hello"'

'''
单引号注释
'''

"""
双引号注释
"""

a = 5
b = 3
if a > b:
    print("a is big")
else:
    print("b is big")



c = "ssss"
if c is not None:
    print(c)



num = 89
if num >90:
    print("优秀")
elif num > 60:
    print("良好")
else:
    print("不及格")

# 循环
# 借助range()方法
for i in range(1,101,2):
    print(i)

x = "hello"
y = ['a','b']
for i in x:
    print(i)
for i in y:
    print(i)


# 数组=list=列表
print("--------------")
shuzu = ["a",'b',1,2]
# 追加
shuzu.append(3)
# 替换
shuzu[1] = 'c'
# 删除
shuzu.pop(0)
for i in shuzu:
    print(i)

# 元组，不允许追加、替换
yuanzu=("a",'b',1,2)
# 删除元祖
del yuanzu



# 字典,key:value成对出现，一个key对应一个value，key不能重复
value = "vv"
zidian = {"key":value,"key2":value}
print (zidian)

# 字典的另外一种写法
value = "vv"
zidian = {}
zidian.update(
    {"key":value,"key2":value}
)
print (zidian)

# 字典的删除
#del zidian['key2']
#print (zidian)

print(zidian.keys())
print(zidian.values())

for k,v in zidian.items():
    print("--")
    print(k)
    print(v)

data = {

    "success":"true",
    'data':[
        {"id":1,"name":"tom"},
        {"id":2,"name":"jack"}
    ]
}

print(data['data'][1]['name'])