python 关于linux命令行

python 使用命令行

Use python to set env

读取环境变量

# Import os module  
import os  
  
# Iterate loop to read and print all environment variables  
print("The keys and values of all environment variables:")  
for key in os.environ:  
 print(key, '=>', os.environ[key])  
  
# Print the value of the particular environment variable  
print("The value of HOME is: ", os.environ['HOME'])

查看环境变量是否设置

# Import os module  
import os  
# Import sys module  
import sys  
  
while True:  
 # Take the name of the environment variable  
 key_value = input("Enter the key of the environment variable:")  
  
 # Check the taken variable is set or not  
 try:  
	 if os.environ[key_value]:  
		 print("The value of", key_value, " is ", os.environ[key_value])  
	 # Raise error if the variable is not set  
	 except KeyError:  
		 print(key_value, 'environment variable is not set.')  
	 # Terminate from the script  
 sys.exit(1)

设置环境变量

# Import os module  
import os  
  
# Set the value DEBUG variable  
os.environ.setdefault('DEBUG', 'True')  
  
# Checking the value of the environment variable  
if os.environ.get('DEBUG') == 'True':  
 print('Debug mode is on')  
else:  
 print('Debug mode is off')

设置命令行

import subprocess
import os
def command(command_line):
    process = subprocess.Popen(command_line,
    stdout=subprocess.PIPE, 
    stderr=subprocess.PIPE)
    stdout, stderr = process.communicate()
    stderr = stderr.decode('utf-8')
    stdout = stdout.decode('utf-8')
    print("stdout ",stdout,";stderr ",stderr)

command(['command','arg','aeg'])

def split_str_by_blank(str_com,split_char = ""):

 # str 是字符串，默认用空格分割

 # para

 # @str_com -> string 待分割的字符串

 # @split_char -> string 分割标志

 # @return -> list 分割输出

 if not split_char:

 str_list = str_com.split()

 else:

 str_list = str_com.split(split_char)

 return str_list


def command_print_out_err(str_com):

 # 用来执行命令，并且根据是否报错输出err 或者 out

 # para

 # @str_com -> string 输入命令

 # @print 输出 err 或者 out

 str_list = split_str_by_blank(str_com)

 err , out = commandline(str_list)

 if err :

 print("ERROR ! : \n",err)

 elif out :

 print("OUTPUT : \n",out)

踩坑

• 不要使用 str , command 之类的关键字作为函数/函数名，都可能会报 str object is not callable