独立于语言环境的字符串在python中进行浮点转换

Question

I need to convert string to float, but there can be different input string formats, such as '1234,5' or '1234.5' or '1 234,5' or '1,234.5' or whatever. And I can not change locale decimal pointer or thousands separator, because I may not know what data I will get in advance.

Is there a way or method or library to parse and convert to float this kind of locale-specific values without knowing which locale is used?

PS Is there any solution exists for the same problem with dates?

TIA.

Answer 1

You can make some assumptions on which character is the thousands separator and which is the decimal point. However, there is a case where you cannot know for sure what do do:

• Look for the last character that is . or , . If it occurs more than once, the number does not have a decimal point and that character is the thousands separator
• If the string contains exactly one of each, the last one is the decimal point
• If the string contains only one point/comma, you are pretty much out of luck: 123.456 or 123,456 might be the number 123456 or 123.456 . However, with a number like 123.45 - ie the number of digits after the potential thousands separator not being a multiple of three - you can assume that it's a decimal point.