Python:对元组使用较低的函数 [英] Python: Using lower function on tuples

问题描述

我是Python的新手，已经看了很多文档来弄清楚发生了什么，但是没有任何运气.

I'm new to Python and have looked at quite a bit of documentation to figure out what is going on, but haven't had any luck.

我有一个元组列表，我需要将其转换为小写并对列表中的所有值执行数学运算.为了执行数学运算，"E"必须变为"e".

I have a list of tuples that I need to convert to lowercase and perform mathematical operations on all values in the list. The "E", needs to become an "e" in order to perform mathematical operations.

如果给定的元组列表中只有一个值，则可以执行以下操作:

If there is a single value in a given list of tuples, the following works:

EarthU = ['1.3719107E+11', '8.3311764E-02', '2.2719107E+11', '1.4880643E+03']
earthU = [element.lower() for element in EarthU]
earthU = [(0.3048*0.3048)*float(element) for element in earthU]

如果给定的元组列表中每个元组有多个值，我尝试相同的逻辑:

If there are more than one value for each tuple in a given list of tuples and I try the same logic:

EarthV = [('4.2997980E+12', '7.5608735E+13'), (1.8986931E+00', '3.0367303E+02'), ('3.4997980E+12', '7.5608735E+13'), ('-4.9202352E+04', '2.8277192E+06')]
earthV = [element.lower() for element in EarthV]

当尝试将元组中的每个元素转换为小写时，我收到以下错误:

And I receive the following error when trying to convert each element in the tuple to lowercase:

AttributeError:"tuple"对象没有属性"lower"

AttributeError: 'tuple' object has no attribute 'lower'

我有一种感觉，当我尝试执行数学运算时，我遇到的此属性错误也会成为问题. 谢谢.

I have a feeling that this attribute error I am running into will become a problem when I try to perform the mathematical operations as well. Thanks.

推荐答案

将字符串解析为浮点数可同时使用大写字母'E'和小写字母'e'.

Parsing of string to a floating point number works with both uppercase 'E' and lowercase 'e'.

您的代码可以缩短为:

EarthU = ['1.3719107E+11', '8.3311764E-02', '2.2719107E+11', '1.4880643E+03']
earthU = [(0.3048*0.3048)*float(element) for element in earthU]

对于元组，您可以通过提取元组的元素来使用单个列表理解(因为元组本身不具有.lower()方法，但其元素却具有):

And for tuples you can use a single list comprehension by extracting the elements of tuples (since tuple itself doesn't have .lower() method but its elements do):

EarthV = [('4.2997980E+12', '7.5608735E+13'), ('1.8986931E+00', '3.0367303E+02'), ('3.4997980E+12', '7.5608735E+13'), ('-4.9202352E+04', '2.8277192E+06')]
earthV = [(float(x), float(y)) for x,y in EarthV]

如果您确实需要小写字母:

If you really need lowercase:

earthV = [(x.lower(), y.lower()) for x,y in EarthV]

此形式for x,y in EarthV通过获取元组元素的第一部分并将其绑定到x并将元组的第二部分绑定到y来破坏EarthV的元素.

This form for x,y in EarthV destructures the element of EarthV by taking the first part of the tuple element and binds it to x and the second part of the tuple binds to y.

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