python 包含列表和字符串的字符串格式

Question

我想使用字符串格式将变量值插入到 mystring 中，其中一些变量是正常值，一些是列表值。

myname = 'tom'
mykids = ['aa', 'bb', 'cc']
mystring = """ hello my name is %s and this are my kids %s, %s, %s """ 
    % (myname, tuple(mykids))

我得到了参数不足的错误，因为我可能 tuple(mykids) 做错了。帮助赞赏。

Answer 1

您可以使用 str.format() 代替：

>>> myname = 'tom'
>>> mykids = ['aa','bb','cc']
>>> mystring = 'hello my name is {} and this are my kids {}, {}, {}'.format(myname, *mykids)
>>> print mystring
hello my name is tom and this are my kids aa, bb, cc

请注意 *mykids 的使用，它解压列表并将每个列表项作为单独的参数传递给 format()。

但是请注意，格式字符串被硬编码为仅接受 3 个孩子。更通用的方法是使用 str.join():

将列表转换为字符串

>>> mystring = 'hello my name is {} and this are my kids {}'.format(myname, ', '.join(mykids))
>>> print mystring
hello my name is tom and this are my kids aa, bb, cc
>>> mykids.append('dd')
>>> mystring = 'hello my name is {} and this are my kids {}'.format(myname, ', '.join(mykids))
>>> print mystring
hello my name is tom and this are my kids aa, bb, cc, dd

后一种方法也适用于字符串插值：

>>> mystring = 'hello my name is %s and this are my kids %s' % (myname, ', '.join(mykids))
>>> print mystring
hello my name is tom and this are my kids aa, bb, cc, dd

最后你可能想要处理只有一个的情况 child:

>>> one_kid = 'this is my kid'
>>> many_kids = 'these are my kids'
>>> mystring = 'hello my name is {} and {} {}'.format(myname, many_kids if len(mykids) > 1 else one_kid, ', '.join(mykids))
>>> print mystring
hello my name is tom and these are my kids aa, bb, cc, dd
>>> mykids = ['aa']
>>> mystring = 'hello my name is {} and {} {}'.format(myname, many_kids if len(mykids) > 1 else one_kid, ', '.join(mykids))
>>> print mystring
hello my name is tom and this is my kid aa

Answer 2

这是一种方法：

%(myname, mykids[0], mykids[1], mykids[2])

Answer 3

这是另一种可能的方式，

在 python 2.7.6 这行得通：

myname = 'Njord'
mykids = ['Jason', 'Janet', 'Jack']
print "Hello my name is %s and these are my kids,", % myname
for kid in kids:
    print kid

Answer 4

>>> mystring=" hello my name is %s and this are my kids %s, %s, %s " %((myname,) + tuple(mykids))
>>> mystring
' hello my name is tom and this are my kids aa, bb, cc '

python 包含列表和字符串的字符串格式

python string format with both list and string

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