一、int的范圍

python2：

　　在32位機器上，整數的位數為32位，取值范圍為-2**31～2**31-1；
　　在64位系統上，整數的位數為64位，取值范圍為-2**63～2**63-1；

python3：

　　理論上長度是無限的（只要內存足夠大）

二、python內存機制

在一般情況下當變量被賦值后，內存和變量的關系如下：

特殊情況：

python內的優化機制（不論是2.7還是3.5都有）：

-5 ~ 257 之間的數，如果使用第一種賦值方式，那么他們依然屬于同一塊內存（可以用id查看）

三、源碼

  1 class int(object):
  2     """
  3     int(x=0) -> int or long
  4     int(x, base=10) -> int or long
  5     
  6     Convert a number or string to an integer, or return 0 if no arguments
  7     are given.  If x is floating point, the conversion truncates towards zero.
  8     If x is outside the integer range, the function returns a long instead.
  9     
 10     If x is not a number or if base is given, then x must be a string or
 11     Unicode object representing an integer literal in the given base.  The
 12     literal can be preceded by '+' or '-' and be surrounded by whitespace.
 13     The base defaults to 10.  Valid bases are 0 and 2-36.  Base 0 means to
 14     interpret the base from the string as an integer literal.
 15     >>> int('0b100', base=0)
 16     """
 17     def bit_length(self): 
 18         """ 返回表示該數字的時占用的最少位數 """
 19         """
 20         int.bit_length() -> int
 21         
 22         Number of bits necessary to represent self in binary.
 23         >>> bin(37)
 24         '0b100101'
 25         >>> (37).bit_length()
 26         """
 27         return 0
 28 
 29     def conjugate(self, *args, **kwargs): # real signature unknown
 30         """ 返回該復數的共軛復數 """
 31         """ Returns self, the complex conjugate of any int. """
 32         pass
 33 
 34     def __abs__(self):
 35         """ 返回絕對值 """
 36         """ x.__abs__() <==> abs(x) """
 37         pass
 38 
 39     def __add__(self, y):
 40         """ x.__add__(y) <==> x+y """
 41         pass
 42 
 43     def __and__(self, y):
 44         """ x.__and__(y) <==> x&y """
 45         pass
 46 
 47     def __cmp__(self, y): 
 48         """ 比較兩個數大小 """
 49         """ x.__cmp__(y) <==> cmp(x,y) """
 50         pass
 51 
 52     def __coerce__(self, y):
 53         """ 強制生成一個元組 """ 
 54         """ x.__coerce__(y) <==> coerce(x, y) """
 55         pass
 56 
 57     def __divmod__(self, y): 
 58         """ 相除，得到商和余數組成的元組 """ 
 59         """ x.__divmod__(y) <==> divmod(x, y) """
 60         pass
 61 
 62     def __div__(self, y): 
 63         """ x.__div__(y) <==> x/y """
 64         pass
 65 
 66     def __float__(self): 
 67         """ 轉換為浮點類型 """ 
 68         """ x.__float__() <==> float(x) """
 69         pass
 70 
 71     def __floordiv__(self, y): 
 72         """ x.__floordiv__(y) <==> x//y """
 73         pass
 74 
 75     def __format__(self, *args, **kwargs): # real signature unknown
 76         pass
 77 
 78     def __getattribute__(self, name): 
 79         """ x.__getattribute__('name') <==> x.name """
 80         pass
 81 
 82     def __getnewargs__(self, *args, **kwargs): # real signature unknown
 83         """ 內部調用 __new__方法或創建對象時傳入參數使用 """ 
 84         pass
 85 
 86     def __hash__(self): 
 87         """如果對象object為哈希表類型，返回對象object的哈希值。哈希值為整數。在字典查找中，哈希值用于快速比較字典的鍵。兩個數值如果相等，則哈希值也相等。"""
 88         """ x.__hash__() <==> hash(x) """
 89         pass
 90 
 91     def __hex__(self): 
 92         """ 返回當前數的 十六進制 表示 """ 
 93         """ x.__hex__() <==> hex(x) """
 94         pass
 95 
 96     def __index__(self): 
 97         """ 用于切片，數字無意義 """
 98         """ x[y:z] <==> x[y.__index__():z.__index__()] """
 99         pass
100 
101     def __init__(self, x, base=10): # known special case of int.__init__
102         """ 構造方法，執行 x = 123 或 x = int(10) 時，自動調用，暫時忽略 """ 
103         """
104         int(x=0) -> int or long
105         int(x, base=10) -> int or long
106         
107         Convert a number or string to an integer, or return 0 if no arguments
108         are given.  If x is floating point, the conversion truncates towards zero.
109         If x is outside the integer range, the function returns a long instead.
110         
111         If x is not a number or if base is given, then x must be a string or
112         Unicode object representing an integer literal in the given base.  The
113         literal can be preceded by '+' or '-' and be surrounded by whitespace.
114         The base defaults to 10.  Valid bases are 0 and 2-36.  Base 0 means to
115         interpret the base from the string as an integer literal.
116         >>> int('0b100', base=0)
117         # (copied from class doc)
118         """
119         pass
120 
121     def __int__(self): 
122         """ 轉換為整數 """ 
123         """ x.__int__() <==> int(x) """
124         pass
125 
126     def __invert__(self): 
127         """ x.__invert__() <==> ~x """
128         pass
129 
130     def __long__(self): 
131         """ 轉換為長整數 """ 
132         """ x.__long__() <==> long(x) """
133         pass
134 
135     def __lshift__(self, y): 
136         """ x.__lshift__(y) <==> x<<y """
137         pass
138 
139     def __mod__(self, y): 
140         """ x.__mod__(y) <==> x%y """
141         pass
142 
143     def __mul__(self, y): 
144         """ x.__mul__(y) <==> x*y """
145         pass
146 
147     def __neg__(self): 
148         """ x.__neg__() <==> -x """
149         pass
150 
151     @staticmethod # known case of __new__
152     def __new__(S, *more): 
153         """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
154         pass
155 
156     def __nonzero__(self): 
157         """ x.__nonzero__() <==> x != 0 """
158         pass
159 
160     def __oct__(self): 
161         """ 返回改值的 八進制 表示 """ 
162         """ x.__oct__() <==> oct(x) """
163         pass
164 
165     def __or__(self, y): 
166         """ x.__or__(y) <==> x|y """
167         pass
168 
169     def __pos__(self): 
170         """ x.__pos__() <==> +x """
171         pass
172 
173     def __pow__(self, y, z=None): 
174         """ 冪，次方 """ 
175         """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """
176         pass
177 
178     def __radd__(self, y): 
179         """ x.__radd__(y) <==> y+x """
180         pass
181 
182     def __rand__(self, y): 
183         """ x.__rand__(y) <==> y&x """
184         pass
185 
186     def __rdivmod__(self, y): 
187         """ x.__rdivmod__(y) <==> divmod(y, x) """
188         pass
189 
190     def __rdiv__(self, y): 
191         """ x.__rdiv__(y) <==> y/x """
192         pass
193 
194     def __repr__(self): 
195         """轉化為解釋器可讀取的形式 """
196         """ x.__repr__() <==> repr(x) """
197         pass
198 
199     def __str__(self): 
200         """轉換為人閱讀的形式，如果沒有適于人閱讀的解釋形式的話，則返回解釋器課閱讀的形式"""
201         """ x.__str__() <==> str(x) """
202         pass
203 
204     def __rfloordiv__(self, y): 
205         """ x.__rfloordiv__(y) <==> y//x """
206         pass
207 
208     def __rlshift__(self, y): 
209         """ x.__rlshift__(y) <==> y<<x """
210         pass
211 
212     def __rmod__(self, y): 
213         """ x.__rmod__(y) <==> y%x """
214         pass
215 
216     def __rmul__(self, y): 
217         """ x.__rmul__(y) <==> y*x """
218         pass
219 
220     def __ror__(self, y): 
221         """ x.__ror__(y) <==> y|x """
222         pass
223 
224     def __rpow__(self, x, z=None): 
225         """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
226         pass
227 
228     def __rrshift__(self, y): 
229         """ x.__rrshift__(y) <==> y>>x """
230         pass
231 
232     def __rshift__(self, y): 
233         """ x.__rshift__(y) <==> x>>y """
234         pass
235 
236     def __rsub__(self, y): 
237         """ x.__rsub__(y) <==> y-x """
238         pass
239 
240     def __rtruediv__(self, y): 
241         """ x.__rtruediv__(y) <==> y/x """
242         pass
243 
244     def __rxor__(self, y): 
245         """ x.__rxor__(y) <==> y^x """
246         pass
247 
248     def __sub__(self, y): 
249         """ x.__sub__(y) <==> x-y """
250         pass
251 
252     def __truediv__(self, y): 
253         """ x.__truediv__(y) <==> x/y """
254         pass
255 
256     def __trunc__(self, *args, **kwargs): 
257         """ 返回數值被截取為整形的值，在整形中無意義 """
258         pass
259 
260     def __xor__(self, y): 
261         """ x.__xor__(y) <==> x^y """
262         pass
263 
264     denominator = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
265     """ 分母 = 1 """
266     """the denominator of a rational number in lowest terms"""
267 
268     imag = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
269     """ 虛數，無意義 """
270     """the imaginary part of a complex number"""
271 
272     numerator = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
273     """ 分子 = 數字大小 """
274     """the numerator of a rational number in lowest terms"""
275 
276     real = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
277     """ 實屬，無意義 """
278     """the real part of a complex number"""
279 
280 int

int

小知識點：

在python2中：

test = 9 / 2 
輸出—— 4

from __future__ import division
test = 9 / 2 
輸出—— 4.5

而在python3中：

test = 9 / 2 
輸出—— 4.5

總結

以上是生活随笔為你收集整理的python基本数据类型——int的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。