CPU 输出为 csv 格式 - python

Question

I'm trying to get the entire CPU output in the csv format. But it prints only the last line in the csv output. Can someone look into this and help me on correcting the below script.

   import paramiko
   import subprocess
   import csv
   myfile = open(r"file input path")
   txt = myfile.read()
   client = paramiko.SSHClient()
   target_host = txt
   un = 'root'
   pwd = 'xxx'
   client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
   client.connect(hostname=target_host,username=un,password=pwd)
   stdin, stdout, stderr = client.exec_command('ps -aux')
   for line in stdout:
      with open("cpuoutput.csv", "w", newline="") as f:
           f.write(line)
   print (line) 

Answer 1

When you open file with mode "w" (write) then it removes previous countent

so you should open file only once - before loop

with open("cpuoutput.csv", "w", newline="") as f:
    for line in stdout:
        f.write(line)
        print (line) 

or you have to use mode "a" (append) to keep previous content

  for line in stdout:
       with open("cpuoutput.csv", "a", newline="") as f:
            f.write(line)
       print (line) 

---

First method should be faster for bigger files because it doesn't have to close and reopen file for every line.

Second method can be safer when script can get crush because often system saves data on disk not when Python write() but when Python close() file - so closing after every line can keep previous lines on disk when there is cruch.