gh-77065: Add optional keyword-only argument echo_char for getpass.getpass

Doc/library/getpass.rst

@@ -16,7 +16,7 @@
 
 The :mod:`getpass` module provides two functions:
 
-.. function:: getpass(prompt='Password: ', stream=None)
+.. function:: getpass(prompt='Password: ', stream=None, *, echochar=None)
 
    Prompt the user for a password without echoing.  The user is prompted using
    the string *prompt*, which defaults to ``'Password: '``.  On Unix, the
@@ -25,6 +25,12 @@ The :mod:`getpass` module provides two functions:
    (:file:`/dev/tty`) or if that is unavailable to ``sys.stderr`` (this
    argument is ignored on Windows).
 
+   The *echochar* argument controls how user input is displayed while typing.
+   If *echochar* is ``None`` (default), input remains hidden. If *echochar* is
+   a string, each typed character is replaced with the given string.
+   For example, ``echochar='*'`` will display asterisks instead of the actual
+   input.
+
    If echo free input is unavailable getpass() falls back to printing
    a warning message to *stream* and reading from ``sys.stdin`` and
    issuing a :exc:`GetPassWarning`.
@@ -33,6 +39,9 @@ The :mod:`getpass` module provides two functions:
       If you call getpass from within IDLE, the input may be done in the
       terminal you launched IDLE from rather than the idle window itself.
 
+   .. versionchanged:: next
+      Added the *echochar* parameter for keyboard feedback.
+
 .. exception:: GetPassWarning
 
    A :exc:`UserWarning` subclass issued when password input may be echoed.

Doc/whatsnew/3.14.rst

@@ -558,6 +558,16 @@ getopt
 * Add support for returning intermixed options and non-option arguments in order.
   (Contributed by Serhiy Storchaka in :gh:`126390`.)
 
+
+getpass
+-------
+
+* Support keyboard feedback by :func:`getpass.getpass` via the keyword-only
+  optional argument ``echochar``. Placeholder characters are rendered whenever
+  a character is entered, and removed when a character is deleted.
+  (Contributed by Semyon Moroz in :gh:`77065`.)
+
+
 http
 ----
 

Lib/getpass.py

@@ -1,6 +1,7 @@
 """Utilities to get a password and/or the current user name.
 
-getpass(prompt[, stream]) - Prompt for a password, with echo turned off.
+getpass(prompt[, stream[, echochar]]) - Prompt for a password, with echo
+turned off and optional keyboard feedback.
 getuser() - Get the user name from the environment or password database.
 
 GetPassWarning - This UserWarning is issued when getpass() cannot prevent
@@ -25,13 +26,15 @@
 class GetPassWarning(UserWarning): pass
 
 
-def unix_getpass(prompt='Password: ', stream=None):
+def unix_getpass(prompt='Password: ', stream=None, *, echochar=None):
     """Prompt for a password, with echo turned off.
 
     Args:
       prompt: Written on stream to ask for the input.  Default: 'Password: '
       stream: A writable file object to display the prompt.  Defaults to
               the tty.  If no tty is available defaults to sys.stderr.
+      echochar: A string used to mask input (e.g., '*').  If None, input is
+                hidden.
     Returns:
       The seKr3t input.
     Raises:
@@ -40,6 +43,10 @@ def unix_getpass(prompt='Password: ', stream=None):
 
     Always restores terminal settings before returning.
     """
+    if echochar and not echochar.isascii():
+        return ValueError(f"Invalid echochar: {echochar}. "
+                          "ASCII character expected.")
+
     passwd = None
     with contextlib.ExitStack() as stack:
         try:
@@ -68,12 +75,20 @@ def unix_getpass(prompt='Password: ', stream=None):
                 old = termios.tcgetattr(fd)     # a copy to save
                 new = old[:]
                 new[3] &= ~termios.ECHO  # 3 == 'lflags'
+                if echochar:
+                    new[3] &= ~termios.ICANON
                 tcsetattr_flags = termios.TCSAFLUSH
                 if hasattr(termios, 'TCSASOFT'):
                     tcsetattr_flags |= termios.TCSASOFT
                 try:
                     termios.tcsetattr(fd, tcsetattr_flags, new)
-                    passwd = _raw_input(prompt, stream, input=input)
+                    if not echochar:
+                        passwd = _raw_input(prompt, stream, input=input)
+                        stream.write('\n')
+                        return passwd
+
+                    passwd = _input_with_echochar(prompt, stream, input,
+                                                  echochar)
                 finally:
                     termios.tcsetattr(fd, tcsetattr_flags, old)
                     stream.flush()  # issue7208
@@ -93,10 +108,13 @@ def unix_getpass(prompt='Password: ', stream=None):
         return passwd
 
 
-def win_getpass(prompt='Password: ', stream=None):
+def win_getpass(prompt='Password: ', stream=None, *, echochar=None):
     """Prompt for password with echo off, using Windows getwch()."""
     if sys.stdin is not sys.__stdin__:
         return fallback_getpass(prompt, stream)
+    if echochar and not echochar.isascii():
+        return ValueError(f"Invalid echochar: {echochar}. "
+                          "ASCII character expected.")
 
     for c in prompt:
         msvcrt.putwch(c)
@@ -108,9 +126,15 @@ def win_getpass(prompt='Password: ', stream=None):
         if c == '\003':
             raise KeyboardInterrupt
         if c == '\b':
+            if echochar and pw:
+                msvcrt.putwch('\b')
+                msvcrt.putwch(' ')
+                msvcrt.putwch('\b')
             pw = pw[:-1]
         else:
             pw = pw + c
+            if echochar:
+                msvcrt.putwch(echochar)
     msvcrt.putwch('\r')
     msvcrt.putwch('\n')
     return pw
@@ -151,6 +175,33 @@ def _raw_input(prompt="", stream=None, input=None):
     return line
 
 
+def _input_with_echochar(prompt, stream, input, echochar):
+    if not stream:
+        stream = sys.stderr
+    if not input:
+        input = sys.stdin
+    prompt = str(prompt)
+    stream.write(prompt)
+    stream.flush()
+    passwd = ""
+    while True:
+        char = input.read(1)
+        if char == '\n' or char == '\r':
+            break
+        if char == '\x03':
+            raise KeyboardInterrupt
+        if char == '\x7f' or char == '\b':
+            if passwd:
+                stream.write("\b \b")
+                stream.flush()
+            passwd = passwd[:-1]
+        else:
+            passwd += char
+            stream.write(echochar)
+            stream.flush()
+    return passwd
+
+
 def getuser():
     """Get the username from the environment or password database.
 

Misc/NEWS.d/next/Library/2025-02-24-07-08-11.gh-issue-77065.8uW0Wf.rst

@@ -0,0 +1,2 @@
+Add keyword-only optional argument *echochar* for :meth:`getpass.getpass`
+for optional visual keyboard feedback support. Patch by Semyon Moroz.