"""Reads a character from standard input.

If the user enters a newline, an empty string is returned. For the most

part, this behaves just like input(). An optional prompt can be

provided.

"""

print(prompt, end='')

sys.stdout.flush()

# Windows

try:

char = msvcrt.getwch()

except NameError:

pass

else:

if char == '\r' or char == '\n':

char = ''

print(char, end='')

sys.stdout.flush()

return char

# Unix

file_number = sys.stdin.fileno()

try:

old_settings = termios.tcgetattr(file_number)

except NameError:

pass

except termios.error:

pass

else:

tty.setcbreak(file_number)

try:

char = chr(27)

if sys.stdin.isatty():

# avoid escape sequences and other undesired characters

while ord(char[0]) in (8, 27, 127):

char = sys.stdin.read(len(sys.stdin.buffer.peek(1)))

else:

char = sys.stdin.read(1)

if char == '\r' or char == '\n':

char = ''

if 'old_settings' in locals():

print(char, end='')

sys.stdout.flush()

finally:

try:

termios.tcsetattr(file_number, termios.TCSADRAIN, old_settings)

except NameError:

pass