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Python Time & Space Complexity

Pty

pty Module¶

The pty module provides pseudo-terminal utilities for Unix systems, enabling control of terminal-like processes.

Complexity Reference¶

Operation	Time	Space	Notes
`fork()`	O(1)	O(1)	Create pseudo-terminal
I/O handling	O(n)	O(n)	n = data size

Pseudo-Terminal Operations¶

Spawning Terminal Process¶

import pty
import subprocess
import sys

# Spawn interactive process - O(1)
pty.spawn(['bash'])

# Equivalent to:
# bash shell with full terminal support

Fork with PTY¶

import pty
import os

# Fork with pseudo-terminal - O(1)
pid, master_fd = pty.fork()

if pid == 0:
    # Child process - O(1)
    os.execv('/bin/bash', ['/bin/bash'])
else:
    # Parent process - O(n)
    while True:
        try:
            data = os.read(master_fd, 1024)
            sys.stdout.buffer.write(data)
        except OSError:
            break

    os.close(master_fd)
    os.waitpid(pid, 0)