问题
I have an array in python that contains a set of values, some of them are
2.32313e+07
2.1155e+07
1.923e+07
11856
112.32
How do I convert the exponential formats to the decimal format
Additional: Is there a way I can convert the exponent directly to decimal when printing out in UNIX with awk?
回答1:
I imagine you have a list rather than an array, but here it doesn't make much of a difference; in 2.6 and earlier versions of Python, something like:
>>> L = [2.32313e+07, 2.1155e+07, 1.923e+07, 11856, 112.32]
>>> for x in L: print '%f' % x
...
23231300.000000
21155000.000000
19230000.000000
11856.000000
112.320000
and in 2.6 or later, the .format method. I imagine you are aware that the numbers per se, as numbers, aren't in any "format" -- it's the strings you obtain by formatting the numbers, e.g. for output, that are in some format. BTW, variants on that %f can let you control number of decimals, width, alignment, etc -- hard to suggest exactly what you may want without further specs from you.
In awk, you can use printf.
回答2:
You can use locale.format() to format your numbers for output. This has the additional benefit of being consistent with any locale-specific conventions that might be expected in the presentation of the numbers. If you want complete control at the specific place where you do the output, you'd be better of with the print "format" % vars... variant.
Example:
>>> import locale
>>> locale.setlocale(locale.LC_ALL, "")
'C/UTF-8/C/C/C/C'
>>> locale.format("%f", 2.32313e+07, 1)
'23231300.000000'
回答3:
In answer to the last part of your question, awk can use the same printf format:
awk '{printf "%f\n",$1}' exponential_file
Where exponential_file contains:
2.32313e+07
2.1155e+07
1.923e+07
11856
112.32
You can do the conversion into a variable for use later. Here is a simplistic example:
awk '{n = sprintf("%f\n",$1); print n * 2}' exponential_file
来源：https://stackoverflow.com/questions/1573080/convert-exponential-to-decimal-in-python