Converting 5.223701009526849e-05 to 5e-05

Sun May 3 04:40:38 EDT 2015

Cecil Westerhof <Cecil at decebal.nl> writes:
> When I have a value like 5.223701009526849e-05 in most cases I am not
> interested in all the digest after the dot.

What type of value is it?
A ‘float’ value has many different textual representations, most of them
inaccurate. So talking about the digits of a ‘float’ value is only
partly meaningful; digits are a property of some chosen representation,
not intrinsic to the number.
A ‘str’ value can be converted in various ways, but is useless as a
number until you create a new number from the result.
Choosing a solution will rely on understanding that the textual
representation of a number is not itself a number; and vice versa, a
number value does not have a canonical text representation.
> Is there a simple way to convert it to a string like '5e-05'?

Assuming we're talking about a ‘float’ value::
 >>> foo = 5.223701009526849e-05
 >>> "{foo:5.1}".format(foo=foo)
 '5e-05'
See the ‘str.format’ documentation, especially the detailed
documentation for the “format specification mini-language”
<URL:https://docs.python.org/3/library/string.html#format-specification-mini-language>
for how to specify exactly how you want values to be formatted as
text.
-- 
 \ “The double standard that exempts religious activities from |
 `\ almost all standards of accountability should be dismantled |
_o__) once and for all.” —Daniel Dennett, 2010年01月12日 |
Ben Finney