Question

我目前正在学习python，想知道这两个打印语句有何不同？我的意思是两者都执行相同的操作，但只是语法不同。还有其他差异吗？

a = 5
b = 'hi'

print "The number is", a, " and the text is", b

print "The number is %d and the text is %s" %(a, b)

Answer 1

如果变量a不是数字，第二个将失败。

>>> a='hi'
>>> b='hi'
>>> print "The number is %d and the text is %s" %(a, b)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-3-aa94a92667a1> in <module>()
----> 1 print "The number is %d and the text is %s" %(a, b)

TypeError: %d format: a number is required, not str

如果a始终是一个数字，它们会表现得非常相似，除了格式中的%d强制它是一个整数，所以如果你有：

>>> a=1.2
>>> b='hi'
>>> print "The number is %d and the text is %s" %(a, b)
The number is 1 and the text is hi

您可以看到它将数字1.2转换为整数1。

根据评论，另一个选项是使用format function，其行为类似于您的第一个选项但使用format string：

>>> a=1.2
>>> b='hi'
>>> print "The number is {} and the text is {}".format(a, b)
The number is 1.2 and the text is hi

它还允许使用命名参数：

>>> print "The number is {number} and the text is {text}".format(number=a, text=b)
The number is 1.2 and the text is hi

使用％和变量名在python中打印变量

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