如何有选择地在Python字符串中转义百分比(%)？

Question

我有以下代码

test = "have it break."
selectiveEscape = "Print percent % in sentence and not %s" % test

print(selectiveEscape)

我想获得输出:

Print percent % in sentence and not have it break.

实际发生了什么:

    selectiveEscape = "Use percent % in sentence and not %s" % test
TypeError: %d format: a number is required, not str

Answer 1

>>> test = "have it break."
>>> selectiveEscape = "Print percent %% in sentence and not %s" % test
>>> print selectiveEscape
Print percent % in sentence and not have it break.

Answer 2

或者,从Python 2.6开始,您可以使用新的字符串格式(在PEP 3101中描述):

'Print percent % in sentence and not {0}'.format(test)

当你的琴弦变得更复杂时,这尤其方便.

Answer 3

尝试使用%%打印%符号.

Answer 4

如果您使用的是Python 3.6或更高版本，则可以使用f-string：

>>> test = "have it break."
>>> selectiveEscape = f"Print percent % in sentence and not {test}"
>>> print(selectiveEscape)
... Print percent % in sentence and not have it break.

Answer 5

您不能有选择地逃避%,因为%总是具有特殊含义,具体取决于以下字符.

在Python 的文档中,在该部分的第二个表的bottem中,它指出:

'%'        No argument is converted, results in a '%' character in the result.

因此你应该使用:

selectiveEscape = "Print percent %% in sentence and not %s" % (test, )

(请注意将元组的expicit更改为参数%)

如果不知道上述内容,我会做到:

selectiveEscape = "Print percent %s in sentence and not %s" % ('%', test)

凭借你显然已经拥有的知识.