查找PID函数使用不返回任何东西

Question

我有一个函数，它应该使用psutil返回给定进程的进程ID，但由于某种原因它没有返回任何东西。

打印所需变量显示正确的值。我想我做错了什么。

def pid_find(process_name):
   pid = []
   for proc in psutil.process_iter():
     try:
        if proc.name() == process_name:
            pid.append(proc.pid)
     except psutil.AccessDenied:
        pass
   try:
     process = pid[0]
   except IndexError:
     raise Exception("Process %s not found" % process_name)
   print process # prints the correct value
   return process # does not return anything

Answer 1

加上适当的缩进，它看起来应该是这样的-

def pid_find(process_name):
    pid = []
    for proc in psutil.process_iter():
        try:
            if proc.name() == process_name:
                pid.append(proc.pid)
        except psutil.AccessDenied:
            pass
    try:
        process = pid[0]
    except IndexError:
        raise Exception("Process %s not found" % process_name)
    print process #prints the correct value
    return process # return value

Answer 2

可以使用wmi查询而无需迭代:

from win32com.client import Dispatch
import wmi
server = Dispatch("WbemScripting.SWbemLocator")
c = server.ConnectServer("localhost", "root\cimv2")
process_query = "Select * from Win32_Process Where Namse like '%{0}%'".format(cmd_argument)
process = c.ExecQuery(process_query)
for i in process[0].Properties_:
    if i.Name == 'ProcessId':
        return i.Value

Answer 3

我只是试着测试你的代码。它是工作的，除了这个:

if proc.name() == process_name:

必须替换为:

if proc.name == process_name:

用一些简化，但是用你的代码精神:

   import psutil
   def pid_find(process_name):
      for proc in psutil.process_iter():
        try:
           if proc.name == process_name:
              return proc.pid
        except psutil.AccessDenied:
           pass
      raise Exception("Process %s not found" % process_name)
   print pid_find("bash")

Answer 4

我想我找到问题了。该函数工作正常，但我没有正确调试以检查该函数是否工作:

我是这样尝试的:

函数位于文件functions.py file
我像这样调用test.py文件中的函数:

import functions
def debug
   functions.pid_find("chrome.exe) 
if __name__ == "__main__":
    debug()

但是如果我把函数放入一个变量中，我应该能够存储结果并进一步使用它:

import functions
def debug(proc):
    pid = functions.pid_find(proc)
    print pid #shows that pid has the correct value