枚举溢出 [英] enumerate overflow
问题描述
大家好，
python2.4中的
，我从一个文件中读取行，其中包含
for lineNum，行枚举（f） ）：...
但是，lineNum很快就会溢出并开始向后计数。如何使用
i force枚举返回长整数？
干杯。
Hello all,
in python2.4, i read lines from a file with
for lineNum, line in enumerate(f): ...
However, lineNum soon overflows and starts counting backwards. How do
i force enumerate to return long integer?
Cheers.
推荐答案
cr**@post.cz schrieb：
cr**@post.cz schrieb:
大家好，
在python2.4中，我从一个文件中读取行，其中包含
for lineNum，以enumerate（f）行： ...
但是，lineNum很快就会溢出并开始向后计数。怎么做
我强制枚举返回长整数？
Hello all,
in python2.4, i read lines from a file with
for lineNum, line in enumerate(f): ...
However, lineNum soon overflows and starts counting backwards. How do
i force enumerate to return long integer?
最有可能你不能，因为它是我认为的C语言函数。
但是作为python 2.4有生成器，自己创建枚举很容易：
def lenumerate（f）：
i = 0
for line in f：
收益我，行
i + = 1
Diez
Most probably you can''t, because it is a C-written function I presume.
But as python 2.4 has generators, it''s ease to create an enumerate yourself:
def lenumerate(f):
i = 0
for line in f:
yield i, line
i += 1
Diez
cr**@post.cz 写道：
你好所有，在$ python2.4中的
，我从一个文件中读取行，其中包含
的lineNum，枚举（f）行：...
但是，lineNum很快就会溢出并开始向后计数。怎么做
我强制枚举返回长整数？
Hello all,
in python2.4, i read lines from a file with
for lineNum, line in enumerate(f): ...
However, lineNum soon overflows and starts counting backwards. How do
i force enumerate to return long integer?
如何很快你究竟从文件中读取了sys.maxint行吗？我b / b
应该认为需要花费大量时间才能获得
读取2,147,483,647行...
但是它确实，Python 2.5使用enumobject表示，
将索引限制为（C）long：
typedef struct {
PyObject_HEAD
long en_index; / *当前枚举索引* /
PyObject * en_sit; / *枚举的辅助迭代器* /
PyObject * en_result; / *结果元组* /
} enumobject;
问候
Steve
-
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC / Ltd http://www.holdenweb.com
Skype：holdenweb http://del.icio.us/steve.holden
对不起，狗吃了我的.sigline
Just how "soon" exactly do you read sys.maxint lines from a file? I
should have thought that it would take a significant amount of time to
read 2,147,483,647 lines ...
But it is true that Python 2.5 uses an enumobject representation that
limits the index to a (C) long:
typedef struct {
PyObject_HEAD
long en_index; /* current index of enumeration */
PyObject* en_sit; /* secondary iterator of enumeration */
PyObject* en_result; /* result tuple */
} enumobject;
regards
Steve
--
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC/Ltd http://www.holdenweb.com
Skype: holdenweb http://del.icio.us/steve.holden
Sorry, the dog ate my .sigline
> for lineNum，enumerate（f）中的行：...
>for lineNum, line in enumerate(f): ...
>>
但是，lineNum很快就会溢出并开始向后计数。如何强制枚举返回长整数？
>>
However, lineNum soon overflows and starts counting backwards. How do
i force enumerate to return long integer?
如何很快你究竟从文件中读取了sys.maxint行吗？我b $ b应该认为需要花费大量时间才能获得
读取2,147,483,647行...
Just how "soon" exactly do you read sys.maxint lines from a file? I
should have thought that it would take a significant amount of time to
read 2,147,483,647 lines ...
适度（但不是压倒性地）很长时间：
（定义我们自己的xrange-ish生成器，它可以处理比
大于longs的东西）
A modestly (but not overwhelmingly) long time:
(defining our own xrange-ish generator that can handle things
larger than longs)
>> def xxrange（x）：
>>def xxrange(x):
.... i = 0
....而i< x：
....收益我
.... i + = 1
....
.... i = 0
.... while i < x:
.... yield i
.... i += 1
....
>> for i，j in enumerate（xxrange（2 ** 33））：断言i == j
>>for i,j in enumerate(xxrange(2**33)): assert i==j
....
Traceback（最近一次调用最后一次）：
文件"< stdin>"，第1行，在？
断言错误
我花了大约60-90分钟来打断一个断言
双核2.8ghz机器在轻载下。如果
批量处理冗长的日志文件或其他大数据如
基因数据，则完全有可能达到此限制为OP
被发现。
-tkc
....
Traceback (most recent call last):
File "<stdin>", line 1, in ?
AssertionError
It took me about an 60-90 minutes to hit the assertion on a
dual-core 2.8ghz machine under otherwise-light-load. If
batch-processing lengthy log files or other large data such as
genetic data, it''s entirely possible to hit this limit as the OP
discovered.
-tkc
这篇关于枚举溢出的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
