argsparse yes python Standard module for command line parsing , Built in python, No installation required . This library allows us to pass parameters into the program directly from the command line and let the program run .
Location of official documents ：【https://docs.python.org/zh-cn/3/library/argparse.html】
Here we use git To demonstrate command line operation
git -h
git -version
git show
1. Guide pack ：
import argparse
2. Create objects ：
parser = argparse.ArgumentParser()
3. Add parameter ：
parser.add_argument()
4. Analytical parameters ：
parser.parse_args()
parser = ArgumentParser(prog=None, usage=None,description=None, epilog=None, parents=[],formatter_class=argparse.HelpFormatter, prefix_chars='-',fromfile_prefix_chars=None, argument_default=None,conflict_handler='error', add_help=True)
Parameter description ：
prog： Name of program , The default is sys.argv[0], Used in help The name of the program described in the messageusag： A string describing the purpose of the programdescription：help The text in front of the messageepilog：help Information after informationadd_help： Whether to add help informationprefix_chars： Parameter prefixes , The default is-fromfile_prefix_chars： Prefix characters , Before the file nameargument_default： Global default values for parametersconflict_hander： How to deal with conflicts , The default is to return an error “error”. also “resolve”, Intelligent conflict resolution . When the user adds two same command parameters to the program ,“error” Just report the mistake directly , Remind users . and “resolve” Will remove some or all of the repeated command parameters for the first time （ It may be short command conflicts or all conflicts ）
add_argument(name or flags...[, action][, nargs][, const][, default][, type][, choices][, required][, help][, metavar][, dest])
Parameter description ：
name or flags： There are two kinds of parameters , Optional and positional parameters .parse_args()Runtime , Will use-To authenticate the optional parameters , The rest is the position parameter . Position parameter must be selected , Optional parameters are optional# Optional parameters parser.add_argument("-f", "--foo") # Positional arguments parser.add_argument("bar") # Position parameters must be input during operation
action： action ,argparsebuilt-in 6 Actions can be triggered when a parameter is parsed
store： Save parameter values , You may first convert the parameter value to another data type . The default action is this
store_const： Save a value defined as part of the parameter specification , Instead of a value parsed from a parameter . This is often used to implement non Boolean command line tags
stroe_true/store_false： Save the corresponding Boolean value , These two actions are used to implement Boolean switches
append： Save values to a list . If the parameter repeats , Save multiple values
append_const： Save a value defined in the parameter specification to a list
version： Print version information about the program , And then quitparse.add_argument('--version',action = 'version',version = '%(prog)s2.0')
nargs： Number of parameters
- The value can be an integer ,*（ Any number of ）,+（ One or more ）
- First get the parameters from the command line , If not, follow
constget , And then fromdefaultgetdest： The parameter value is saved asparse_args()The returned namespace object is thisdestA property of the parameter value . Provideddest="a", So you can go throughargs.aAccess this parameterdefault： Set the default value of the parametertype： Convert the result entered from the command line to the set typechoice： Allowed parameter valuesrequires： Whether the choicedesk： Can be used as a parameter namehelp： Parameter command introduction
Several ways to write parameters ：
python py.py -i 1 # Use spaces to separate
python py.py --integer=1 # Long options are separated by an equal sign
python py.py -i1 # Short options can be written together
args = parser.parse_args() # The parameters of the command line can be passed in brackets
args_ = parser.parse_args("-i=1".split("="))
We can create a template ：
#!/usr/bin/env python
# -*- coding: UTF-8 -*-
__author__ = "A.L.Kun"
__file__ = "demo01.py"
__time__ = "2022/6/16 17:12"
__email__ = "[email protected]"
from typing import Callable
from functools import wraps
import sys, argparse
def terminal(param: bool = False): # Determine if you want to use command-line arguments
def get_params(fun: Callable):
if param:
parser = argparse.ArgumentParser(description="help document")
"---------------------------------------------------------------"
# If you need to pass in parameters from the command line , Add... Here
"---------------------------------------------------------------"
args = parser.parse_args()
else:
args = None
@wraps(fun)
def inner():
ret = fun(args) # You may need to perform other initialization operations while transferring parameters
return ret
return inner
return get_params
@terminal() # Use decorators
def main(args):
print(args)
if __name__ == "__main__":
main()
sys.exit(0)
Use cases , Create a program , You can connect to the mailbox SMTP service
#!/usr/bin/env python
# -*- coding: UTF-8 -*-
__author__ = "A.L.Kun"
__file__ = "demo01.py"
__time__ = "2022/6/16 17:12"
__email__ = "[email protected]"
from smtplib import SMTP
from typing import Callable
from functools import wraps
import sys, argparse
def terminal(param: bool = False):
def get_params(fun: Callable):
if param:
parser = argparse.ArgumentParser(description="help document")
"---------------------------------------------------------------"
parser.add_argument('--version', "-v", action='version', version='%(prog)s 2.0')
parser.add_argument("-u", "--username", type=str, help="Enter the SMTP server account", required=True)
parser.add_argument("-p", "--password", type=str, help="Enter the SMTP server password", required=True)
"---------------------------------------------------------------"
args = parser.parse_args()
else:
args = None
@wraps(fun)
def inner():
ret = fun(args)
return ret
return inner
return get_params
@terminal(True)
def main(args):
smtp = SMTP('smtp.qq.com')
smtp.login(args.username, args.password)
smtp.quit()
smtp.close()
if __name__ == "__main__":
main()
sys.exit(0)
Send you a complete set of exclusive Python code for Valentines Day (robbery)
Today is Valentines Day , Give
物無定味適口者珍，Python3並發場景(CPU密集/IO密集)任務的並發方式的場景抉擇(多線程threading/多進程multiprocessing/協程asyncio)
原文轉載自「劉悅的技術博客」https://v3u.cn/a
