Records

Get key name from Python KeyError exception

try:
    x2 = myDict['key2']
except KeyError as e:    
    print e.args[0]

How to print without newline or space?

print('.', end='')

String r

r is a prefix for string literals. This means, r"1\2\3\4" will not interpret as an escape when creating the string value, but keep as an actual character in the string. Thus, r"1\2\3\4" will have seven characters.

var = "1\2\3\4" will interpret backslashes as escapes, create the string '1\x02\x03\x04' (a four-character string), then assign this string to the variable var.

程序暂停

import time
time.sleep(amount) #单位s

捕获ctrl-C

使用KeyboardInterrupt捕获异常ref.

try:
    # DO THINGS
except KeyboardInterrupt:
    # quit
    sys.exit()