在python中,如何找到带引号的数字列表的平均值?
我有两种类型的列表。第一个不带引号,该工作并打印平均罚款:在python中,如何找到带引号的数字列表的平均值?,python,linux,unix,Python,Linux,Unix,我有两种类型的列表。第一个不带引号,该工作并打印平均罚款: l = [15,18,20] print l print "Average: ", sum(l)/len(l) 这张照片是: [15,18,20] Average: 17 第二个列表中的数字带有引号,返回一个错误: x = ["15","18","20"] print x print "Average: ", sum(x)/len(x) 错误是: TypeError: unsupported operand type(s) for
l = [15,18,20]
print l
print "Average: ", sum(l)/len(l)
这张照片是:
[15,18,20]
Average: 17
第二个列表中的数字带有引号,返回一个错误:
x = ["15","18","20"]
print x
print "Average: ", sum(x)/len(x)
错误是:
TypeError: unsupported operand type(s) for +: 'int' and 'str'
如何计算引号中包含数值的列表?首先需要将它们转换为
int
:
x = ["15","18","20"]
print sum(map(int,x))/len(x)
此处
map
将x的每个元素映射为整数类型引号表示您有一个字符串列表:
>>> x = ["15","18","20"]
>>> type(x[0])
<type 'str'>
>>>
或者,您可以使用(许多Python程序员更喜欢):
下面是一个演示:
>>> x = ["15","18","20"]
>>> x = map(int, x)
>>> x
[15, 18, 20]
>>> type(x[0])
<type 'int'>
>>> sum(x) / len(x)
17
>>>
x=[“15”、“18”、“20”]
>>>x=映射(int,x)
>>>x
[15, 18, 20]
>>>类型(x[0])
>>>总和(x)/长度(x)
17
>>>
你需要记住除以列表的
len
,我已经挠头很久了。谢谢你,伙计@你又回来了!谢谢你的帮助,伙计,这很好用@黑客狂
x = ["15","18","20"]
x = [int(i) for i in x]
>>> x = ["15","18","20"]
>>> x = map(int, x)
>>> x
[15, 18, 20]
>>> type(x[0])
<type 'int'>
>>> sum(x) / len(x)
17
>>>
print "Average of {list} is: {avg}".format(
list=l,
avg=sum(int(x) for x in l) / len(l),
)