flush

Question: Is there a way to use flush=True for the print() function without getting the BrokenPipeError ? I have a script pipe.py : for i in range(4000): print(i) I call it like this from a Unix command line: python3 pipe.py | head -n3000 And it returns: 0 1 2 So does this script: import sys for i in range(4000): print(i) sys.stdout.flush() However, when I run this script and pipe it to head -n3000 : for i in range(4000): print(i, flush=True) Then I get this error: print(i, flush=True) BrokenPipeError: [Errno 32] Broken pipe Exception BrokenPipeError: BrokenPipeError(32, 'Broken pipe') in <_io

HttpListener gives you response stream, but calling flush means nothing (and from sources it's clear, because it's actually doing nothing). Digging inside HTTP API shows that this is a limitation of HttpListener itself. Anyone knows exactly how to flush response stream of HttpListener (may be with reflection or additional P/Invokes)? Update: You can't http stream anything if you don't have a flush option or ability to define buffer size. Flush only works in most of the System.Net namespace when Transfer-Encoding is set to Chuncked, else the whole request is returned and Flush really does

I have written a daemon that writes a value in a file. What I have observed is that when I keep writing on a file, there is nothing visible in the file. in other hand, If I use fflush() method then the characters are visible in the file. Why fflush() makes a difference? Because it's buffered . That means all writes are stored in a buffer in memory until the buffer is flushed. For printf and friends it's when it has either a newline, or you explicitly call fflush , or of course if the buffer becomes full. By default, stdio is fully buffered, unless it's writing to a terminal, in which case it's