What is sys.maxint in Python 3?
Question:
I’ve been trying to find out how to represent a maximum integer, and I’ve read to use "sys.maxint". However, in Python 3 when I call it I get:
AttributeError: module 'object' has no attribute 'maxint'
Answers:
The sys.maxint constant was removed, since there is no longer a limit to the value of integers. However, sys.maxsize can be used as an integer larger than any practical list or string index. It conforms to the implementation’s “natural” integer size and is typically the same as sys.maxint in previous releases on the same platform (assuming the same build options).
Python 3 ints do not have a maximum.
If your purpose is to determine the maximum size of an int in C when compiled the same way Python was, you can use the struct module to find out:
>>> import struct
>>> platform_c_maxint = 2 ** (struct.Struct('i').size * 8 - 1) - 1
If you are curious about the internal implementation details of Python 3 int objects, Look at sys.int_info for bits per digit and digit size details. No normal program should care about these.
As pointed out by others, Python 3’s int does not have a maximum size, but if you just need something that’s guaranteed to be higher than any other int value, then you can use the float value for Infinity, which you can get with float("inf").
In Python 3.5 onwards, you can use math.inf.
Note: as per ely’s comment, this may impact the efficiency of your code, so it may not be the best solution.
Python 3.0 doesn’t have sys.maxint any more since Python 3’s ints are of
arbitrary length. Instead of sys.maxint it has sys.maxsize; the maximum
size of a positive sized size_t aka Py_ssize_t.
If you are looking for a number that is bigger than all others:
Method 1:
float('inf')
Method 2:
import sys
max = sys.maxsize
If you are looking for a number that is smaller than all others:
Method 1:
float('-inf')
Method 2:
import sys
min = -sys.maxsize - 1
Method 1 works in both Python2 and Python3. Method 2 works in Python3. I have not tried Method 2 in Python2.
An alternative is
import math
... math.inf ...
I’ve been trying to find out how to represent a maximum integer, and I’ve read to use "sys.maxint". However, in Python 3 when I call it I get:
AttributeError: module 'object' has no attribute 'maxint'
The
sys.maxintconstant was removed, since there is no longer a limit to the value of integers. However,sys.maxsizecan be used as an integer larger than any practical list or string index. It conforms to the implementation’s “natural” integer size and is typically the same assys.maxintin previous releases on the same platform (assuming the same build options).
Python 3 ints do not have a maximum.
If your purpose is to determine the maximum size of an int in C when compiled the same way Python was, you can use the struct module to find out:
>>> import struct
>>> platform_c_maxint = 2 ** (struct.Struct('i').size * 8 - 1) - 1
If you are curious about the internal implementation details of Python 3 int objects, Look at sys.int_info for bits per digit and digit size details. No normal program should care about these.
As pointed out by others, Python 3’s int does not have a maximum size, but if you just need something that’s guaranteed to be higher than any other int value, then you can use the float value for Infinity, which you can get with float("inf").
In Python 3.5 onwards, you can use math.inf.
Note: as per ely’s comment, this may impact the efficiency of your code, so it may not be the best solution.
Python 3.0 doesn’t have sys.maxint any more since Python 3’s ints are of
arbitrary length. Instead of sys.maxint it has sys.maxsize; the maximum
size of a positive sized size_t aka Py_ssize_t.
If you are looking for a number that is bigger than all others:
Method 1:
float('inf')
Method 2:
import sys
max = sys.maxsize
If you are looking for a number that is smaller than all others:
Method 1:
float('-inf')
Method 2:
import sys
min = -sys.maxsize - 1
Method 1 works in both Python2 and Python3. Method 2 works in Python3. I have not tried Method 2 in Python2.
An alternative is
import math
... math.inf ...