in python what is this?how,what this cod did?

Question

>>> a=123456789123456789123456789.123456789123456789
>>> print(a)
1.2345678912345679e+26

Answer 1

@Dinmukhamed is right

Answer 2

Changes to scientific notation of a number:
e+26 means ×10^26

Answer 3

Unlike hardware based binary floating point, the decimal module has a user alterable precision (defaulting to 28 places) which can be as large as needed for a given problem:

>>> from decimal import *
>>> getcontext().prec = 6
>>> Decimal(1) / Decimal(7) # Decimal('0.142857')
>>> getcontext().prec = 28
>>> Decimal(1) / Decimal(7) # Decimal('0.1428571428571428571428571429')

source:
https://docs.python.org/2/library/decimal.html
https://docs.python.org/3/library/decimal.html

Answer 4

Floating point numbers are stored as:
significand * base^exponent

In short, this *always* is the best possible *approximation* of a given number. For some numbers, as long as they can be represented fully in the binary system, the approximation is 100%. But for majority of real numbers, there is a finite precision that the number can be represented.

And scientific notation does just that - it tells you how good an approximation this is.

Answer 5

>>> a=33.5
>>> print(a)
33.5

then why it's not print all values(all no which before decimal point) of a .

Answer 6

1.2345678912345679e+26

it is a standard notation to represent large numbers.
therefore the output is to be interpreted as 1.2345678912345679 x 10^26

also notice that there is loss of precision in the output or the answer is shortened ; I have no idea about that .