python视频笔记之二（字典，条件语句）

字典

dic={'name':'milo','age':25,'gender':'male'}

dic['name']

del(dic['age'])

dic.clear()

del(dic)

dic.get(2)                                  dic.get(5,'error')

help(dict.keys)

dic.keys()

dic.values()

for k in dic:

 print k

 print dic[k]

---

if expression:

   statement(s)             使用4个空格代替缩进

---

if expression:

    statement(s)

else:

    statement(s)

---

if expression:

    satement(s)

elseif expression2:

    statement(s)

elseif expression3:

   statement(s)

else:

   statement(s)

x=int(raw_input("please input:"))

if x>=90:

    print "A"

elseif x>=80:

    print "B"

else:

   print "C"

---

逻辑运算符 or    and    not

---

for iteratin_var in sequence:

    statements(s)

for x in [0,1,2,3,4]:

    print x,"hello world"

for x in range[100]: 从0到99增长

fox in in range[1,11,2]:从1到10增长，步进值2

---

for遍历数据

s="hellow"
for k in s:
 print k

for k in range(len(s)):
    print s[k]

dic={1:111,2:222,3:333}

for x in dic:

    print x     输出key值

    print dic[x]  输出value值

print dic.items()  输出全部值

for x,y in dic.items():

    print x,y  输出全部值

  time.sleep(1)延时1秒

   for x in range(1,11):

    print x

    if x==3:

         pass             占位

    if x==2:

       print "hello 2"

       continue       

    if x==5:

      exit()    跳出整个循环

    if x==6:

       break

     print "#"*5

else:

    print "ending"