import sys
# print(sys.platform) #Determine the operating system
# print(sys.path) #python's environment variables
# sys.path.append(r'E:\syz\ly-code\day5') #Add environment variables
# sys.path.insert(0,r'E:\syz\ly-code\day5') #Add environment variables, and put the environment variable path in the first place
# print(sys.argv) #Used to get the parameters passed in when running the python file on the command line
sys.argv
is used to get the parameters passed in when running the python file on the command line. It is a list.
This list has one parameter by default, which is the current file name.
Example:
import sys
import os
command = sys.argv
print(command)
if len(command)>1:
cmd1 = command[1]
if cmd1=='--help':
print('this is the help document'
'this python The file is used to explain the role of sys.argv')
elif cmd1=='os':
print('The current operating system is %s'%sys.platform)
else:
print('The input command is wrong')
else:
print ('Pass in a parameter when running python'
'eg '
'python xx.py install ')
Note:
The order in which python imports modules:
1. Find the python file to be imported from the current directory
2. Find sys.path from the python environment variable
The essence of importing the module:
this python file is executed from start to finish
import nhy
nhy.my()
print(nhy.name)
from nhy import my,name,
my()
print(name)
Both ways are the same
from nhy import * is deprecated