problems using pythom tempfile module
Hello everyone, I'm trying to test the tempfile module with the following script, which basically creates a temporary file, fills the file with some test data and prints it. import tempfile t = tempfile.TemporaryFile() t.write(lalalala) t.flush() print t.read() Unfortunately, the print statement gives me an empty string. Can somebody tell me what I'm doing wrong ? regards Samir -- http://mail.python.org/mailman/listinfo/python-list
Re: problems using pythom tempfile module
On Sep 15, 11:11 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hello everyone, I'm trying to test the tempfile module with the following script, which basically creates a temporary file, fills the file with some test data and prints it. import tempfile t = tempfile.TemporaryFile() t.write(lalalala) t.flush() print t.read() Unfortunately, the print statement gives me an empty string. Can somebody tell me what I'm doing wrong ? regards Samir Do a t.seek(0) before you do the read to rewind the file and then it should work. -- http://mail.python.org/mailman/listinfo/python-list
Re: problems using pythom tempfile module
On Sep 15, 5:24 pm, buffi [EMAIL PROTECTED] wrote: On Sep 15, 11:11 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hello everyone, I'm trying to test the tempfile module with the following script, which basically creates a temporary file, fills the file with some test data and prints it. import tempfile t = tempfile.TemporaryFile() t.write(lalalala) t.flush() print t.read() Unfortunately, the print statement gives me an empty string. Can somebody tell me what I'm doing wrong ? regards Samir Do a t.seek(0) before you do the read to rewind the file and then it should work. Ok, this really worked. Can you elaborate why I have to insert this statement? -- http://mail.python.org/mailman/listinfo/python-list
Re: problems using pythom tempfile module
[EMAIL PROTECTED] wrote: On Sep 15, 5:24 pm, buffi [EMAIL PROTECTED] wrote: On Sep 15, 11:11 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hello everyone, I'm trying to test the tempfile module with the following script, which basically creates a temporary file, fills the file with some test data and prints it. import tempfile t = tempfile.TemporaryFile() t.write(lalalala) t.flush() print t.read() Unfortunately, the print statement gives me an empty string. Can somebody tell me what I'm doing wrong ? regards Samir Do a t.seek(0) before you do the read to rewind the file and then it should work. Ok, this really worked. Can you elaborate why I have to insert this statement? Each file has a current position. As you write a file the current position moves to stay just ahead of what's been written. So if you read it without resetting the current position (back to the beginning with seek(0)) you will get an immediate end of file (i.e. 0 bytes) returned. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden Sorry, the dog ate my .sigline -- http://mail.python.org/mailman/listinfo/python-list
Re: problems using pythom tempfile module
Pretend that you have a number that is always pointing somewhere in your temporary file. It starts a 0. If you then write lalalala (8 characters) it will point after these at position 8, so that you can write more stuff after your previous text later by calling write. The read method reads all the data from the current position of the pointer to the end of the file. If you simply call it after writing, you wont get anything since you are already at the end of the file. Therefore you rewind the pointer back to the start by calling seek which takes the position in the file to go to... your_file.seek(0) returns you to the start of the file to read all of its data - Björn Kempén -- http://mail.python.org/mailman/listinfo/python-list
