标签：cep bytes 长度 join use wro utf-8 stdout on()
# Author:larlly
‘‘‘
函数
1.在Python交互式命令行下，可以直接输入代码，然后执行，并立刻得到结果。
2.文本编辑器推荐俩款
http://www.sublimetext.com/
https://notepad-plus-plus.org/
3.python运行助手 learning.py
1 # Author:larlly 2 # python运行助手 3 r‘‘‘ 4 learning.py 5 6 A Python 3 tutorial from http://www.liaoxuefeng.com 7 8 Usage: 9 10 python3 learning.py 11 ‘‘‘ 12 13 import sys 14 15 def check_version(): 16 v = sys.version_info 17 if v.major == 3 and v.minor >= 4: 18 return True 19 print(‘Your current python is %d.%d. Please use Python 3.4.‘ % (v.major, v.minor)) 20 return False 21 22 if not check_version(): 23 exit(1) 24 25 import os, io, json, subprocess, tempfile 26 from urllib import parse 27 from wsgiref.simple_server import make_server 28 29 EXEC = sys.executable 30 PORT = 39093 31 HOST = ‘local.liaoxuefeng.com:%d‘ % PORT 32 TEMP = tempfile.mkdtemp(suffix=‘_py‘, prefix=‘learn_python_‘) 33 INDEX = 0 34 35 def main(): 36 httpd = make_server(‘127.0.0.1‘, PORT, application) 37 print(‘Ready for Python code on port %d...‘ % PORT) 38 httpd.serve_forever() 39 40 def get_name(): 41 global INDEX 42 INDEX = INDEX + 1 43 return ‘test_%d‘ % INDEX 44 45 def write_py(name, code): 46 fpath = os.path.join(TEMP, ‘%s.py‘ % name) 47 with open(fpath, ‘w‘, encoding=‘utf-8‘) as f: 48 f.write(code) 49 print(‘Code wrote to: %s‘ % fpath) 50 return fpath 51 52 def decode(s): 53 try: 54 return s.decode(‘utf-8‘) 55 except UnicodeDecodeError: 56 return s.decode(‘gbk‘) 57 58 def application(environ, start_response): 59 host = environ.get(‘HTTP_HOST‘) 60 method = environ.get(‘REQUEST_METHOD‘) 61 path = environ.get(‘PATH_INFO‘) 62 if method == ‘GET‘ and path == ‘/‘: 63 start_response(‘200 OK‘, [(‘Content-Type‘, ‘text/html‘)]) 64 return [b‘<html><head><title>Learning Python</title></head><body><form method="post" action="/run"><textarea name="code" style="width:90%;height: 600px"></textarea><p><button type="submit">Run</button></p></form></body></html>‘] 65 if method == ‘GET‘ and path == ‘/env‘: 66 start_response(‘200 OK‘, [(‘Content-Type‘, ‘text/html‘)]) 67 L = [b‘<html><head><title>ENV</title></head><body>‘] 68 for k, v in environ.items(): 69 p = ‘<p>%s = %s‘ % (k, str(v)) 70 L.append(p.encode(‘utf-8‘)) 71 L.append(b‘</html>‘) 72 return L 73 if host != HOST or method != ‘POST‘ or path != ‘/run‘ or not environ.get(‘CONTENT_TYPE‘, ‘‘).lower().startswith(‘application/x-www-form-urlencoded‘): 74 start_response(‘400 Bad Request‘, [(‘Content-Type‘, ‘application/json‘)]) 75 return [b‘{"error":"bad_request"}‘] 76 s = environ[‘wsgi.input‘].read(int(environ[‘CONTENT_LENGTH‘])) 77 qs = parse.parse_qs(s.decode(‘utf-8‘)) 78 if not ‘code‘ in qs: 79 start_response(‘400 Bad Request‘, [(‘Content-Type‘, ‘application/json‘)]) 80 return [b‘{"error":"invalid_params"}‘] 81 name = qs[‘name‘][0] if ‘name‘ in qs else get_name() 82 code = qs[‘code‘][0] 83 headers = [(‘Content-Type‘, ‘application/json‘)] 84 origin = environ.get(‘HTTP_ORIGIN‘, ‘‘) 85 if origin.find(‘.liaoxuefeng.com‘) == -1: 86 start_response(‘400 Bad Request‘, [(‘Content-Type‘, ‘application/json‘)]) 87 return [b‘{"error":"invalid_origin"}‘] 88 headers.append((‘Access-Control-Allow-Origin‘, origin)) 89 start_response(‘200 OK‘, headers) 90 r = dict() 91 try: 92 fpath = write_py(name, code) 93 print(‘Execute: %s %s‘ % (EXEC, fpath)) 94 r[‘output‘] = decode(subprocess.check_output([EXEC, fpath], stderr=subprocess.STDOUT, timeout=5)) 95 except subprocess.CalledProcessError as e: 96 r = dict(error=‘Exception‘, output=decode(e.output)) 97 except subprocess.TimeoutExpired as e: 98 r = dict(error=‘Timeout‘, output=‘执行超时‘) 99 except subprocess.CalledProcessError as e: 100 r = dict(error=‘Error‘, output=‘执行错误‘) 101 print(‘Execute done.‘) 102 return [json.dumps(r).encode(‘utf-8‘)] 103 104 if __name__ == ‘__main__‘: 105 main()
需要支持HTML5的浏览器：
IE >= 9
Firefox
Chrome
Sarafi
输出函数 print()
输入函数 input()
退出函数 exit()
3.x默认支持中文 2.x需要添加 #-*- coding:utf-8 -*-
‘‘‘
print(‘100 + 200 =‘,100+200 )
print("hello world ","你好，世界")
print(1024 * 768)
#python基础
#print absolute value of an integet
a = 100
if a>=0:
print(a)
else:
print(-a)
#print 俩行\ \本身也需要转义
print(‘\\\n\\‘)
#转义太多，可以考虑r‘‘
print(r‘\\\\t\\‘)
#如果字符串内部有很多换行，用\n写在一行里不好阅读，为了简化，Python允许用‘‘‘...‘‘‘的格式表示多行内容
print(‘‘‘line1
... line2
... line3‘‘‘)
#上面是在交互式命令行内输入，注意在输入多行内容时，提示符由>>>变为...，提示你可以接着上一行输入。如果写成程序，就是：
print(‘‘‘line1
line2
line3‘‘‘)
#多行字符串‘‘‘...‘‘‘还可以在前面加上r使用
#布尔值可以用and/or/not 对应 与/或/非
print(True)
print(False)
print(True and False)
print(True or False)
print(not True)
#在Python中，通常用全部大写的变量名表示常量：
#运算符/和//， /计算结果浮点数， //地板除，结果是整数
print(10/3)
print(10//3)
#字符编码
# ASCII 一个字节 GB2312 Unicode 俩个字节 GBK GB18030 utf-8 可变长编码
#对于单个字符的编码，Python提供了ord()函数获取字符的整数表示，chr()函数把编码转换为对应的字符
print(ord(‘A‘))
print(ord("中"))
print(chr(123))
#以Unicode表示的str通过encode()方法可以编码为指定的bytes，
name = ‘abc‘
print(name.encode(‘ascii‘))
name1 = ‘且听风吟‘
print(name1.encode(‘utf-8‘))
#我们从网络或磁盘上读取了字节流，那么读到的数据就是bytes。要把bytes变为str，就需要用decode()方法：
#name2 = "b‘abc‘"
#name3 = "b‘\xe4\xb8\x94\xe5\x90\xac\xe9\xa3\x8e\xe5\x90\x9f‘" 且听风吟的字节
print(b‘abc‘.decode(‘ascii‘))
print(b‘\xe4\xb8\x94\xe5\x90\xac\xe9\xa3\x8e\xe5\x90\x9f‘.decode(‘utf-8‘))
#计算str长度(即字节数)函数 len()
print(len(b‘abc‘))
print(len(b‘\xe4\xb8\x94\xe5\x90\xac\xe9\xa3\x8e\xe5\x90\x9f‘))
print(len("且听分吟".encode(‘utf-8‘)))
#可见，1个中文字符经过UTF-8编码后通常会占用3个字节，而1个英文字符只占用1个字节
#py文件中申明了utf-8编码并不意味着你的.py文件就是UTF-8编码的，必须并且要确保文本编辑器正在使用UTF-8 without BOM编码
标签：cep bytes 长度 join use wro utf-8 stdout on()
原文地址：http://www.cnblogs.com/luoliyu/p/6531609.html
