Python编程快速上手----让繁琐的工作自动化（1. python编程基础）

python工具：pycharm配置以及使用

http://blog.csdn.net/hk2291976/article/details/51141868

一.python基础

1.数字运算符

2**3 指数 =8 
22%8 取余 =6 
22//8 整除 =2 
22/8 除法 =2.75 
3*5 乘法 =15 

2.数据类型

整型             -2，0，3
浮点型           -3.5， 0.0，  8.9
字符串型        ‘qq',  'HELLO!', '11CAT'

3.字符串连接和复制

>>> 'Alice'+'Bob'
'AliceBob'
>>> 'Alice'*3
'AliceAliceAlice'

4.变量名规则

不允许：
中划线
空格
数字开头
特殊字符$' python常用变量名：
小写字母开头

5.常用函数

>>> myname=input()     #这里是注释：输入#
liujiao
>>> print('Nice to meet you, myname is ' + myname)#输出#
Nice to meet you, myname is liujiao
>>> spam=input()
100
>>> spam #输入为字符串#
'100'
>>> len('hello') #字符串长度#
5
>>> str(29)#整数转变为字符串#
'29'
>>> int('42')#字符串转变为整型#
42
>>> float('3')#整数转变为浮点数#
3.0
>>> int(7.7))#浮点数转变为整数#
7

二.控制流

 1.布尔值，比较操作符

>>>#==和！=用于所有数据类型的比较#
>>> 44==88
False
>>> 'hello'=='Hello'
False
>>> 23==23.0
True
>>> 23=='23.0'
False
>>> 2!=3
True
>>> 'cat'!='dog'
True
>>>#<和>和<=和>=用于整型和浮点型#

2.布尔操作符

>>> True and True
True
>>> True and False
False
>>> True or False
True
>>> False or False
False
>>> not True
False

3.混合布尔和比较操作符 

>>> (4<5) and (5<6) True
>>> (4<5) and (5<6) or (not 2+2==4)
True

4.if/elseif/else

>>> name = 'Bob'
>>> age = 5
>>> if name =='Alice':
    print('Hi,Alice')
elif age<12:
    print('hi')
else:
    print('hello')

hi

5.while/sys.exit

import sys
while True:　　#当用于条件判断时，0，0.0，‘’（空字符串）被认为是False，其他值被认为是True
    print('Type exit to exit.')
    response = input()
    if response == 'your name':
        sys.exit()   #退出程序
        #break       #退出循环
    print('good job')
print('end')

6.for/range()

for i in range(5):
    print('i is ' + str(i))

for i in range(10,13):
    print('i is ' + str(i))

for i in range(10,20,5):
    print('i is ' + str(i))

三.函数

 1.print()

>>> spam = print('hello')
hello
>>> None == spam
True
>>> print('cat', 'dog','mice')
cat dog mice
>>> print('cat', 'dog','mice', sep=',')
cat,dog,mice
>>> print('one two three' + \
... 'four five')
one two threefour five

2.try/catch

def spam(dividedBy):
    try:
        return 42/dividedBy
    except ZeroDivisionError:
        print('Error')

print(spam(0))
print(spam(2)) #继续执行

输出
Error
None
21.0

def spam(dividedBy):
    return 42/dividedBy

try:
    print(spam(0))
    print(spam(2))  #一旦执行到except语句，就无法返回
except ZeroDivisionError:
    print('Error')

输出
Error

 四.列表

1.一维列表/二维列表/下标/切片

>>> spam=['cat','dog','rice']
>>> spam[0]
'cat'
>>> spam[0:2]
['cat', 'dog']
>>> spam=[['cat','dog','rice'],[10,20,30]]
>>> spam[1][2]
30

2.列表链接和复制

>>> [1,2,3]+['a','b','c']
[1, 2, 3, 'a', 'b', 'c']
>>> [1,2,3]*3
[1, 2, 3, 1, 2, 3, 1, 2, 3]

3.列表删除

>>> spam=['cat','dog','mice']
>>> del spam[2]
>>> spam
['cat', 'dog']

4.in/not in操作符

>>> 'cat' in ['cat','dog']
True
>>> 'mice' not in ['cat','dog']
True

5.多重赋值

>>> spam=['cat','dog','mice']
>>> cat,dog,mice=spam
>>> cat
'cat'
>>> dog
'dog'
>>> mice
'mice'

6.列表的其他方法

>>> spam=['cat','dog','mice']
>>> spam.index('dog')
1
>>> spam.append('monkey')
>>> spam
['cat', 'dog', 'mice', 'monkey']
>>> spam.insert(1,'chicken')
>>> spam
['cat', 'chicken', 'dog', 'mice', 'monkey']
>>> spam.remove('monkey')
>>> spam
['cat', 'chicken', 'dog', 'mice']
>>> spam.insert(1,'chicken')
>>> spam
['cat', 'chicken', 'chicken', 'dog', 'mice']
>>> spam.remove('chicken')  #只能删除第一次出现的chichen
>>> spam
['cat', 'chicken', 'dog', 'mice']
>>> spam = [2,5,-9,8]
>>> spam.sort()
>>> spam
[-9, 2, 5, 8]
>>> spam.sort(reverse=True)
>>> spam
[8, 5, 2, -9]

6.字符串和元组

 

五.字典和结构化数据

1.字典的定义

>>> mycat={'size':'fat','color':'gray','disposition':'loud'}
>>> mycat['size']
'fat'

2.字典与列表

>>> spam=['cat','dog','mouse']
>>> bacon=['dog','cat','mouse']
>>> spam==bacon   #列表是排序的
False
>>> mycat={'size':'fat','color':'gray','disposition':'loud'}
>>> hercat={'color':'gray','disposition':'loud','size':'fat'}
>>> mycat==hercat  #字典是不排序的
True

3.字典的用法

 1）keys, values,items

>>> mycat={'size':'fat','color':'gray','disposition':'loud'}
>>> for k in mycat.keys():
...  print(k)
...
size
color
disposition
>>>
>>>
>>> for v in mycat.values():
...  print(v)
...
fat
gray
loud
>>> for i in mycat.items():
...  print(i)
...
('size', 'fat')
('color', 'gray')
('disposition', 'loud')
>>> list(mycat.keys())
['size', 'color', 'disposition']
>>> for k,v in mycat.items():
...  print('key:' + k + ',value:' + v)
...
key:size,value:fat
key:color,value:gray
key:disposition,value:loud
>>> 'fat' in mycat.values()
True
>>> 'color' in mycat.keys()
True

 2)get(), setdefault()

>>> mycat.get('color', 'white')
'gray'
>>> mycat.get('colors', 'white')
'white'
>>> mycat.setdefault('width',8)
8
>>> mycat.setdefault('width',10)
8
>>> mycat
{'size': 'fat', 'color': 'gray', 'disposition': 'loud', 'width': 8}

4.嵌套的字典和列表

allGuests = {'Alice': {'apples': 5, 'bananas':4},
             'Bob': {'sandwiches':3, 'apples':3},
             'Carol': {'cups':10, 'apple pies': 9}}
def totalBrought(guests, item):
    numbrought = 0
    for k,v in guests.items():
        numbrought = numbrought + v.get(item, 0)
    return numbrought

print('Apples ' + str(totalBrought(allGuests, 'apples')))
print('Cakes ' + str(totalBrought(allGuests, 'cakes')))


D:\liujiao\python3.6.0\python.exe D:/liujiao/pyCharm/test/test.py
Apples 8
Cakes 0

六.字符串操作

1.处理字符串

>>> spam = 'This is Alice\'s cat'
>>> spam
"This is Alice's cat"
>>> """This is test python program,
... written by liujiao"""
'This is test python program,\nwritten by liujiao'
>>> spam[0]
'T'
>>> spam[3:7]
's is'
>>> 'hello' in 'hello world'
True
>>> 'HELLO' in 'hello world'
False

2.有用的字符串方法

 1）upper(), lower(),isupper(),islower()

>>> spam = 'Hello world'
>>> spam = spam.lower()
>>> spam
'hello world'
>>> spam.upper()
'HELLO WORLD'
>>> spam = 'Hello world'
>>> spam.islower()
False
>>> 'abc1234'.islower()
True
>>> '123'.islower()
False
>>> '123'.isupper()
False

 2)isX

 isalpha（）：字符串只包含字母，并且非空。则为true

isalnum（）：字符串只包含字母和数字，并且非空。则为true

isdecimal（）：字符串只包含数字字符，并且非空。则为true

isspace（）：字符串只包含空格，制表符和换行，并且非空。则为true

istitle（）：字符串只包含以大写字母开头，后面都是小写字母的单词。则为true

 3）startswith（），endswith（）

>>> 'hello world'.startswith('hello')
True
>>> 'hello world'.endswith('world')
True

 4）join（），split（）

>>> ','.join(['cat', 'dog','mouse'])
'cat,dog,mouse'
>>>
>>> 'my name is liujiao'.split()
['my', 'name', 'is', 'liujiao']
>>> 'my name is liujiao'.split('m')
['', 'y na', 'e is liujiao']