file = open('FILENAME', mode)

mode --r,w,x,a,b,+

f = open("test.txt", "w")

f.readline() --type str

f.readlines() -- type list

video = {'betaVideo':'beta.avi', 'motionVideo':'motion.mp4', 'videoLength':12}

video['betaVideo'] --> 'beta.avi'

video.get('betaVideo') --> 'beta.avi'

video['check'] --> 'KeyError: 'check''

video.get('check') --> None

video.get('check', 'nothing') --> 'nothing'

video['betaVideo']='test.avi'

--> {'videoLength': 12, 'motionVideo': 'motion.mp4', 'betaVideo': 'test.avi'}

videoFile['director']='sboku'

-->{'director': 'sboku', 'videoLength': 12, 'motionVideo': 'motion.mp4', 'betaVideo': 'test.avi'}

video = dict(betaVideo='betaVideo.avi', motionVideo='motionVideo.mp4', videoLength=100)

-->

{'betaVideo': 'betaVideo.avi', 'motionVideo': 'motionVideo.mp4', 'videoLength': 100}

author = {'Author':'sboku'}

video.update(author)

-->

{'betaVideo': 'betaVideo.avi', 'motionVideo': 'motionVideo.mp4', 'videoLength': 100, 'Author': 'sboku'}

video.keys()

--> dict_keys(['betaVideo', 'motionVideo', 'videoLength', 'Author'])

video.values()

--> dict_values(['betaVideo.avi', 'motionVideo.mp4', 100, 'sboku'])

video.items()

--> dict_items([('betaVideo', 'betaVideo.avi'), ('motionVideo', 'motionVideo.mp4'), ('videoLength', 100), ('Author', 'sboku')])

s ='test.com'

l = list(s) --> ['t', 'e', 's', 't', '.', 'c', 'o', 'm']

l[-1] = 'n' --> ['t', 'e', 's', 't', '.', 'c', 'o', 'n']

s = ''.join(l) --> 'test.con'

s = '3'.join(l) --> 't3e3s3t3.3c3o3n'

url = 'getronics.com,yahoo.co.jp,nikkei.com'

type(url) --> <class 'str'>

url = url.split(',') --> ['getronics.com', 'yahoo.co.jp', 'nikkei.com']

type(url) --> <class 'list'>

url = 'getronics.com'

url.startswith('g') --> True

url.endswith('com') --> True

url.find('getronics') --> 0

url.find('com') --> 10

a,b = 1,2 a -->1, b--> 2

'{0} --> {1}'.format(a,b) --> '1 --> 2'

'{name} --> {age}'.format(name = 'jerry', age = '100') --> 'jerry --> 100'

('{name} --> {age}'.format(name = 'jerry', age = '100')).upper() --> 'JERRY --> 100'

[c*3 for c in 'CODE'] --> ['CCC', 'OOO', 'DDD', 'EEE']

['nikkei.com'] * 3 --> ['nikkei.com', 'nikkei.com', 'nikkei.com']

l = ['nikkei.com']

l.extend(['test.com', 'getronics.com']) --> ['nikkei.com', 'test.com', 'getronics.com']

l[0] --> 'nikkei.com'

l[1] --> 'test.com'

l = ['nikkei.com']

l.append(['test.com', 'getronics.com']) --> ['nikkei.com', ['test.com', 'getronics.com']]

l[0] --> 'nikkei.com'

l[1] --> ['test.com', 'getronics.com']

l.sort(), l.reverse(),

l.index('nikkei.com') --> 0

l.count('nikkei.com') --> 1

l1 = [1, 2, 3, 4, 5]

l2 = l1

l2 --> [1, 2, 3, 4, 5]

l1[0] = 10

l2 --> [10, 2, 3, 4, 5]

l2 = l1[:] or l2 = l1.copy()

l1[0] = 11 --> [11, 2, 3, 4, 5]

l2 --> [10, 2, 3, 4, 5]

'f={0}'.format(x)

'f=x'

'f={0:.3f}'.format(3.333333)

'f=3.333'

d = {'name':'sboku', 'age':'30', 'job':'engineer'}

'name:{0}, age:{1}'.format(d.get('name'), d.get('age'))

10//4 --> 2

10//4.0 -->2.0

import math
math.floor(3.4) -->3 math.floor(3.9) --> 3

math.floor(-3.4) -->-4  math.floor(-3.9) --> -4

math.trunc(3.9) -->3 math.trunc(-3.9) --> -3

0o 8进制, 0x 16进制, 0b 2进制

转换 oct(), hex(), bin()

"what's your name" == 'what\'s your name'

s = "asdfasdfagaf"

s[:] --> 'asdfasdfagaf'

s[-1] --> 'f', s[:-1] --> 'f'

s[::2] --> 'adadaa'

s[::3] --> 'afdg'

解释器，PVM

解释器-- 字节码

PVM执行字节码