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argparse：
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習題：
實現ls命令功能，-l、-a、--all、-h選項：
顯示路徑下的文件列表；
-a和--all顯示包含.開頭的文件；
-l，詳細列表顯示；
-h和-l，人性化顯示文件大小；
c字符，d目錄，-普通文件，l軟鏈接，b塊設備，s socket文件，p pipe文件即FIFO；
按文件名排序輸出，可和ls的順序不一樣；
詳細列表顯示時，時間按“年-月-日 時:分:秒”格式顯示；
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-rw-r--r-- 1 root?? root??? 136 May? 7 09:45 test.json
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mode 硬鏈接 屬主 屬組 字節 時間 文件名
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ls -l /etc
位置參數，參數放在那里，就要對應一個參數位置，如/etc；
選項參數，必須通過前面是-短選項（短選項后面可以沒有參數）或--長選項，然后后面的才算它的參數，如-l；
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程序或腳本在運行時，位置參數必須寫，argparse默認的-h可有可無；
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argparse不僅僅做了參數的定義和解析，還自動幫助生成了幫助信息，尤其是usage，可以看到自定義的參數是否是自己想要的；
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class ArgumentParser(_AttributeHolder, _ActionsContainer):
??? """Object for parsing command line strings into Python objects.
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??? Keyword Arguments:
??????? - prog -- The name of the program (default: sys.argv[0])?? #程序的名字，缺省使用sys.argv[0]
??????? - usage -- A usage message (default: auto-generated from arguments)
??????? - description -- A description of what the program does?? #為程序功能添加描述
??????? - epilog -- Text following the argument descriptions
??????? - parents -- Parsers whose arguments should be copied into this one
??????? - formatter_class -- HelpFormatter class for printing help messages
??????? - prefix_chars -- Characters that prefix optional arguments
??????? - fromfile_prefix_chars -- Characters that prefix files containing
??????????? additional arguments
??????? - argument_default -- The default value for all arguments
??????? - conflict_handler -- String indicating how to handle conflicts
??????? - add_help -- Add a -h/-help option?? #自動為解析器增加-h和--help選項，默認為True
??? """
??? def __init__(self,
???????????????? prog=None,
???????????????? usage=None,
???????????????? description=None,
???????????????? epilog=None,
???????????????? version=None,
???????????????? parents=[],
???????????????? formatter_class=HelpFormatter,
???????????????? prefix_chars='-',
???????????????? fromfile_prefix_chars=None,
? ???????????????argument_default=None,
???????????????? conflict_handler='error',
???????????????? add_help=True):
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??? def add_argument(self, *args, **kwargs):
??????? """
??????? add_argument(dest, ..., name=value, ...)
??????? add_argument(option_string, option_string, ..., name=value, ...)
??????? """
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argparse中add_argument()的action參數，內置6種動作可在解析到一個參數時進行觸發：
store_true|store_false?? #保存相應的布爾值，用于實現布爾開關
store?? #默認，保存參數值，可能會先將參數值轉換成另一個數據類型，若沒顯式指定則為默認
store_const?? #用于實現非布爾值的命令行標記，保存一個被定義為參數規格的值
append?? #將值保存到一個列表中，若參數重復出現，則保存多個值
append_const?? #將定義在參數規格中的值保存到一個列表中
version?? #打印關于程序的版本信息，然后退出
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parser = argparse.ArgumentParser(prog='ls', add_help=True, description='list directory contents')
parser.add_argument('path', nargs='?', default='.', help='path help')
# parser.add_argument('-l')
# parser.add_argument('-l', nargs='?')
parser.add_argument('-l', action='store_true', help='use a long listing format')
parser.add_argument('-a', '--all', action='store_true', help='show all files,do not ignore entries starting with .')?? #長短選項可同時給出
args = parser.parse_args()
print(args)
parser.print_help()
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例：
tests.py
import argparse
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parser = argparse.ArgumentParser()?? #獲得一個參數解析器
args = parser.parse_args()?? #分析參數
parser.print_help()?? #打印幫助
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>python tests.py -h
usage: tests.py [-h]
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optional arguments:
? -h, --help? show this help message and exit
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例：
import argparse
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parser = argparse.ArgumentParser(prog='ls', add_help=True, description='list directory contents')
parser.add_argument('path')?? #path為位置參數，必須提供，否則報error: the following arguments are required
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args = parser.parse_args()
print(args)
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s>python tests.py
usage: ls [-h] path
ls: error: the following arguments are required: path
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例：
import argparse
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parser = argparse.ArgumentParser(prog='ls', add_help=True, description='list directory contents')
parser.add_argument('path')
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args = parser.parse_args(('e:/',))?? #分析參數，同時傳入可迭代的參數，('/etc'.split())或(('/etc'),)或('/etc -all'.split())或(('/etc/','-lah'))；Namespace(path='e:/')里的path可通過Namespace對象訪問，如args.path
print(args)?? #打印名詞空間中收集的參數
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>python tests.py
Namespace(path='e:/')
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例：
import argparse
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parser = argparse.ArgumentParser(prog='ls', add_help=True, description='list directory contents')
parser.add_argument('path', nargs='?', default='.', help='path help')?? #default，給path提供默認值，當前路徑，path也變成可選的；nargs表示這個參數接收結果參數，?表示可有可無；help表示幫助文檔中這個參數的描述
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args = parser.parse_args()
print(args)
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>python tests.py
Namespace(path='.')
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parser.add_argument('-l')?? #效果為
Namespace(l=None, path='.')
usage: ls [-h] [-l L] [path]
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parser.add_argument('-l', nargs='?')?? #效果為
Namespace(l=None, path='.')
usage: ls [-h] [-l [L]] [path]
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parser.add_argument('-l', action='store_true')?? #效果為
Namespace(l=False, path='.')
usage: ls [-h] [-l] [path]
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例：
parser = argparse.ArgumentParser(prog='ls', add_help=False, description='list directory contents')
parser.add_argument('path', nargs='?', default='.', help='path help')
parser.add_argument('-l', action='store_true', help='use a long listing format')
parser.add_argument('-a', '--all', action='store_true', help='show all files,do not ignore entries starting with .')
parser.add_argument('-h', action='store_true', help='making readable easily')
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if __name__ == '__main__':
??? args = parser.parse_args()
??? print('args=', args)
??? # parser.print_help()
??? print(args.path, args.l, args.h, args.all)
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>python tests.py -l -a .
args= Namespace(all=True, h=False, l=True, path='.')
. True False True
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import argparse
from pathlib import Path
import datetime
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import win_unicode_console
win_unicode_console.enable()
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def _convert_mode(mode: int):
??? modelst = ['r', 'w', 'x', 'r', 'w', 'x', 'r', 'w', 'x']?? #modelst = list('rwx'*3)
??? modestr = bin(mode)[-9:]
??? # print(modestr)
??? ret = ''
??? for i, c in enumerate(modestr):
??????? if c == '1':
??????????? ret += modelst[i]
??????? else:
??????????? ret += '-'
??? return ret
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def _convert_human(size: int):
??? # units =? [' ', 'K', 'M', 'G', 'T', 'P']?? # units = list(' KMGTP')
??? units = ' KMGTP'
??? depth = 0
??? while size >= 1000:
??????? size = size // 1000
??????? depth += 1
??? return '{}{}'.format(size, units[depth])
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def _convert_type(file:Path):
??? ret = ''
??? if file.is_dir():
??????? ret = 'd'
??? elif file.is_symlink():
??????? ret = 'l'
??? elif file.is_socket():
??????? ret = 's'
??? elif file.is_block_device():
??????? ret = 'b'
??? elif file.is_char_device():
??????? ret = 'c'
??? else:
??????? ret = '-'
??? return ret
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def showdir(path: str='.', detail=False, all=False, human=False) -> list:
??? p = Path(path)
??? for file in p.iterdir():
??????? # if not all:
??????? #???? if file.name.startswith('.'):
??????? #???????? continue
??????? if not all and file.name.startswith('.'):
??????????????? continue
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??????? if detail:
??????????? st = file.stat()
????????? ??# print(st)?? #os.stat_result(st_mode=33206, st_ino=7599824371282335, st_dev=178462745, st_nlink=1, st_uid=0, st_gid=0, st_size=47, st_atime=1551941978, st_mtime=1551941978, st_ctime=1551928586)
??????????? h = str(st.st_size)
??????????? if human:
???? ???????????h = _convert_human(st.st_size)
??????????? # drwxr-xr-x 9 ane? ane? 4.0K Apr 11 02:40 apache-tomcat-7.0.67
??????????? # (33206, 1, 0, 0, 3031, 1557296696.6941395, 'tests.py')
??????????? # yield (st.st_mode, st.st_nlink, st.st_uid, st.st_gid, st.st_size, st.st_atime, file.name)
??????????? yield (_convert_type(file) + _convert_mode(st.st_mode), st.st_nlink, st.st_uid, st.st_gid, h,
?????????????????? datetime.datetime.fromtimestamp(st.st_atime).strftime('%Y-%m-%d %H:%M:%S'), file.name)
??????? else:
??????? # print(file.name)
??????????? yield file.name
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# print(showdir.__annotations__)
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parser = argparse.ArgumentParser(prog='ls', add_help=False, description='list directory contents')
parser.add_argument('path', nargs='?', default='.', help='path help')
parser.add_argument('-l', action='store_true', help='use a long listing format')
parser.add_argument('-a', '--all', action='store_true', help='show all files,do not ignore entries starting with .')
parser.add_argument('-h', action='store_true', help='making readable easily')
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if __name__ == '__main__':
??? args = parser.parse_args()
??? print('args=', args)
??? # parser.print_help()
??? print('path={} -l={} -h={} -a={}'.format(args.path, args.l, args.h, args.all))
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??? for file in showdir(args.path, detail=args.l, all=args.all, human=args.h):
??????? print(file)
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1、使用stat模塊，
In [29]: help(stat.filemode)
Help on built-in function filemode in module _stat:
filemode(...)
??? Convert a file's mode to a string of the form '-rwxrwxrwx'
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In [24]: p = Path('gis.log')
In [25]: p.stat
Out[25]: <bound method Path.stat of WindowsPath('gis.log')>
In [26]: p.stat()
Out[26]: os.stat_result(st_mode=33206, st_ino=1970324837080203, st_dev=178462745, st_nlink=1, st_uid=0, st_gid=0, st_size=70330, st_atime=1550905696, st_mtime=1550905642, st_ctime=1550905696)
In [27]: p.stat().st_mode
Out[27]: 33206
In [28]: stat.filemode(p.stat().st_mode)
Out[28]: '-rw-rw-rw-'
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2、整合代碼，用到yield from；
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import argparse
from pathlib import Path
import datetime
import stat
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import win_unicode_console
win_unicode_console.enable()
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parser = argparse.ArgumentParser(prog='ls', add_help=False, description='list directory contents')
parser.add_argument('path', nargs='?', default='.', help='path help')
parser.add_argument('-l', action='store_true', help='use a long listing format')
parser.add_argument('-a', '--all', action='store_true', help='show all files,do not ignore entries starting with .')
parser.add_argument('-h', action='store_true', help='making readable easily')
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def showdir(path: str='.',? detail=False, all=False, human=False) -> list:
??? # modelst = ['r', 'w', 'x', 'r', 'w', 'x', 'r', 'w', 'x']? # modelst = list('rwx'*3)
??? # def _convert_mode(mode: int):
??? #???? modestr = bin(mode)[-9:]
??? #???? # print(modestr)
??? #???? ret = ''
??? #???? for i, c in enumerate(modestr):
??? #???????? if c == '1':
??? #???????????? ret += modelst[i]
??? #???????? else:
??? #???????????? ret += '-'
??? #???? return ret
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??? def _convert_human(size: int):
??????? # units =? [' ', 'K', 'M', 'G', 'T', 'P']?? # units = list(' KMGTP')
??????? units = ' KMGTP'
??????? depth = 0
??????? while size >= 1000:
??????????? size = size // 1000
??????????? depth += 1
??????? return '{}{}'.format(size, units[depth])
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??? # def _convert_type(file:Path):
??? #???? ret = ''
??? #???? if file.is_dir():
??? #???????? ret = 'd'
??? #???? elif file.is_symlink():
??? #???????? ret = 'l'
??? #???? elif file.is_socket():
??? #???????? ret = 's'
??? #???? elif file.is_block_device():
??? #???????? ret = 'b'
??? #???? elif file.is_char_device():
??? #???????? ret = 'c'
??? #???? else:
??? #???????? ret = '-'
??? #???? return ret
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??? def _showdir(path: str='.', detail=False, all=False, human=False) -> list:
??????? p = Path(path)
??????? for file in p.iterdir():
??????????? # if not all:
??????????? #???? if file.name.startswith('.'):
??????????? #???????? continue
??????????? if not all and file.name.startswith('.'):
??????????????????? continue
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??????????? if detail:
??????????????? st = file.stat()
??????????????? # print(st)?? #os.stat_result(st_mode=33206, st_ino=7599824371282335, st_dev=178462745, st_nlink=1, st_uid=0, st_gid=0, st_size=47, st_atime=1551941978, st_mtime=1551941978, st_ctime=1551928586)
??????????????? h = str(st.st_size)
??????????????? if human:
??????????????????? h = _convert_human(st.st_size)
??????????????? # drwxr-xr-x 9 ane? ane? 4.0K Apr 11 02:40 apache-tomcat-7.0.67
??????????????? # (33206, 1, 0, 0, 3031, 1557296696.6941395, 'tests.py')
??????????????? # yield (st.st_mode, st.st_nlink, st.st_uid, st.st_gid, st.st_size, st.st_atime, file.name)
??????????????? # yield (_convert_type(file) + _convert_mode(st.st_mode), st.st_nlink, st.st_uid, st.st_gid, h,
?????????????????????? # datetime.datetime.fromtimestamp(st.st_atime).strftime('%Y-%m-%d %H:%M:%S'), file.name)
??????????????? yield (stat.filemode(st.st_mode), st.st_nlink, st.st_uid, st.st_gid, h,
?????????????????????? datetime.datetime.fromtimestamp(st.st_atime).strftime('%Y-%m-%d %H:%M:%S'), file.name)
??????????? else:
??????????? # print(file.name)
??????????????? yield file.name
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??? yield from sorted(_showdir(path, detail, all, human), key=lambda x: x[len(x)-1])
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# print(showdir.__annotations__)
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if __name__ == '__main__':
??? args = parser.parse_args()
??? print('args=', args)
??? # parser.print_help()
??? print('path={} -l={} -h={} -a={}'.format(args.path, args.l, args.h, args.all))
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??? for file in showdir(args.path, detail=args.l, all=args.all, human=args.h):
??????? print(file)
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>python tests.py -lah .
args= Namespace(all=True, h=True, l=True, path='.')
path=. -l=True -h=True -a=True
('-rw-rw-rw-', 1, 0, 0, '47 ', '2019-03-07 14:59:38', '__init__.py')
('drwxrwxrwx', 1, 0, 0, '4K', '2019-04-02 17:15:21', '__pycache__')
('-rw-rw-rw-', 1, 0, 0, '209 ', '2019-03-07 14:42:00', 'admin.py')
('-rw-rw-rw-', 1, 0, 0, '1K', '2019-04-01 13:36:40', 'adminx.py')
('-rw-rw-rw-', 1, 0, 0, '119 ', '2019-03-07 14:59:03', 'apps.py')
('-rw-rw-rw-', 1, 0, 0, '854 ', '2019-03-27 15:12:48', 'forms.py')
('drwxrwxrwx', 1, 0, 0, '4K', '2019-03-07 13:46:16', 'migrations')
('-rw-rw-rw-', 1, 0, 0, '2K', '2019-03-28 16:32:33', 'models.py')
('-rw-rw-rw-', 1, 0, 0, '4K', '2019-05-08 16:05:48', 'tests.py')
('-rw-rw-rw-', 1, 0, 0, '786 ', '2019-03-28 16:10:02', 'urls.py')
('-rw-rw-rw-', 1, 0, 0, '9K', '2019-03-30 15:48:10', 'views.py')
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