python - 附加到每条打印的消息

Question

简单的问题，我想将文本附加到我调用的每个 print 的前面，例如，如果我将文本设置为 hello 并运行以下命令:

print 'hello there'
print ' hi again'

它会打印这个:

hellohello there
hello hi again

有什么方法可以做到这一点，而不使用函数来代替 print 吗？

Answer 1

您可以按照DevPlayer's post here on StackOverflow覆盖打印，此处稍作修改:

from __future__ import print_function
# Note: If you are using Python 3 leave this line out
# This must be the first statement before other statements.
# You may only put a quoted or triple quoted string, 
# Python comments or blank lines before the __future__ line.
import sys

def print(*args, **kwargs):
    """My custom print() function."""
    # Adding new arguments to the print function signature 
    # is probably a bad idea.
    # Instead consider testing if custom argument keywords
    # are present in kwargs
    sys.stdout.write('hello')
    return __builtins__.print(*args, **kwargs)

print ("hello there")
print (" hi again")

[编辑] ...或者按照 DSM 的建议，您可以通过以下方式避免系统调用:

from __future__ import print_function
# Note: If you are using Python 3 leave this line out
# This must be the first statement before other statements.
# You may only put a quoted or triple quoted string, 
# Python comments or blank lines before the __future__ line.

def print(*args, **kwargs):
    """My custom print() function."""
    # Adding new arguments to the print function signature 
    # is probably a bad idea.
    # Instead consider testing if custom argument keywords
    # are present in kwargs
    __builtins__.print('hello',end='')
    return __builtins__.print(*args, **kwargs)

print ("hello there")
print (" hi again")