以“w+”模式打开文件：FileNotFoundError: [Errno 2] No such file or directory

Question

python beginner here. Using mac.

I'm creating a program that saves internet speed tests into a.csv file (appends to existing file, or writes new file if it doesn't exist)

I got this to work with the following:

if exists('internetspeedtimes.csv'):
  with open('internetspeedtimes.csv', 'a+') as f:
    f.seek(0, 0)
    a = f.read()
    f.write('\n')
    f.write(data)
else:
  with open('internetspeedtimes.csv', 'w+') as f:
    f.write(data)

I now want to take this a step further to create a new file each day:

filename = 'InternetSpeedTest_' + now.strftime("%D") + '.csv'

I then use filename instead of 'internetspeedtimes.csv' :

filename = 'InternetSpeedTest_' + now.strftime("%D") + '.csv'
if exists(filename):
    with open(filename, 'a+') as f:
        f.seek(0, 0)
        a = f.read()
        f.write('\n')
        f.write(data)
else:
    with open(filename, 'w+') as f:
        f.write(data)

I get the following error corresponding to the else statement (the 'w+' line):

FileNotFoundError: [Errno 2] No such file or directory: 'InternetSpeedTest_11/24/21.csv'

I've tried:

• Most answers to this question seem to be an issue of directory. However, I also specifying the exact directory:

  filename = '/Users/me/PycharmProjects/pythonProject2/venv' + now.strftime("%D") + '.csv'

Which didn't work. I'm confused because I can get an appropriate answer when feeding a str into open(), but not when feeding an object that is of class str (ie filename).

Thank you very much!

Answer 1

Your filename is being treated as several subdirectories then a file, namely

InternetSpeetTest_11/
  24/
    21.csv

Therefore the "No such file or directory" error is telling you those intermediate directories do not exist. Instead switch to something that doesn't look like a directory such as

'InternetSpeedTest_11-24-21.csv'