Python continue apparently not returning control to while loop

Question

I have a while loop based on a MySQLdb cursor in which I need to move to the next iteration based on some conditions in an if statement. Sanitised code looks like this:

    row = cur.fetchone()

    while row is not None: 
      unique_id = row[0] 
      mac = row[1] 
      url = row[2]

      location = old_path + unique_id 

      os.chdir(location)
      file_count = 0
      for file in os.listdir(location): 
        if file.startswith('phone.') and file.endswith('.cfg'):
            file_count = file_count + 1

      if file_count != 1: 
        userprompt = 'Multiple phone.MAC.RANDOM.cfg files detected continue?'
        cont = query_yes_no(userprompt) # prompt user on what to do next - abort or continue
        if cont == False:
          debugmsg = 'User requested abort - aborting'
          print debugmsg
          logger.info(debugmsg)
          sys.exit()
        elif cont == True:
            debugmsg = 'Moving to next on user request'
            logger.info(debugmsg)
            continue

This code does not behave as expected. When run, if it hits a directory that matches the file_count !=1 condition, the loop appears to run again without advancing to the next row. Unless I have misunderstood the use of continue I thought it should effectively quit that iteration of the loop and move to the next row.

What am I missing?

Answer 1

代替“继续”，您需要获取下一行：row = cur.fetchone（）

Answer 2

You are correct that continue will move to the next iteration.

However, you are not modifying anything in any iteration. Your statement row is not None , in your while never changes. It's either always true or always false.

You probably want to do something like this:

while cur.fetchone() is not None: 
  #your code

Or better yet:

while cur.fetchone(): 
  #your code