Why does python add an 'L' on the end of the result of large exponents?

Question

If you've noticed, python adds an L on to the end of large exponent results like this:

>>> 25 ** 25
88817841970012523233890533447265625L

After doing some tests, I found that any number below 10 doesn't include the L. For example:

>>> 9 ** 9
387420489

This was strange, so, why does this happen, is there any method to prevent it? All help is appreciated!

Because on the C level, I believe that integer is of type `long`. — anon582847382, May 19 '14 at 15:36
Ick, misfired, that wasn't the best dupe. Wasted my hammer there. — Martijn Pieters, May 19 '14 at 15:38
You look at the representation of the number. The number itself does not have a trailing `L`. — Matthias, May 19 '14 at 15:39
@AlexThornton: I would like to see you fit `88817841970012523233890533447265625` into a C long... — Tim Pietzcker, May 19 '14 at 15:39
http://en.wikipedia.org/wiki/Integer_(computer_science)#Long_integer — anon582847382, May 19 '14 at 15:39
Possible duplicate of [Why do integers in database row tuple have an 'L' suffix?](http://stackoverflow.com/q/11764713) — Martijn Pieters, May 19 '14 at 15:40
@AlexThornton A long integer does not correspond to the `long` data type in C; rather it is an arbitrary precision integer implemented by Python. — chepner, May 19 '14 at 15:41

score 48 · Accepted Answer · answered May 19 '14 at 15:38

48

Python supports arbitrary precision integers, meaning you're able to represent larger numbers than a normal 32 or 64 bit integer type. The L tells you when a literal is of this type and not a regular integer.

Note, that L only shows up in the interpreter output, it's just signifying the type. If you print that result instead:

>>> print(25 ** 25)
88817841970012523233890533447265625

The L doesn't get printed.

In Python 3, these types have been merged, so Python 3 outputs:

Python 3.4.0 (default, Apr 11 2014, 13:05:11) 
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 24 ** 24
1333735776850284124449081472843776

answered May 19 '14 at 15:38

Collin

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I know this is a small issue, but since ```print(25**25)``` is clearly Python 3, the ```L``` wouldn't show regardless. – wnnmaw May 19 '14 at 15:42
7

The parens work fine in either version, but yes that is true. – Collin May 19 '14 at 15:48
4

@wnnmaw Why would `print(25**25)` be clearly Python 3? – user189 May 19 '14 at 15:59
2

@user189, because I didn't know ```print(x)``` was valid Python 2 :P I assumed that meant it would be treated like a function, hence Python 3 – wnnmaw May 19 '14 at 16:05

Why does python add an 'L' on the end of the result of large exponents?

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