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open() in Python does not create a file if it doesn't exist
...the file does not exist, it creates a new file for
reading and writing. -Python file modes
seek() method sets the file's current position.
f.seek(pos [, (0|1|2)])
pos .. position of the r/w pointer
[] .. optionally
() .. one of ->
0 .. absolute position
1 .. relative position to current
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How to set up a PostgreSQL database in Django
I'm new to Python and Django.
11 Answers
11
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java.lang.NoClassDefFoundError: Could not initialize class XXX
...ing) and still found nothing.
So, I try to find the difference between the linux machine and my computer. Then I found that this problem happens only when several threads run in one process(By the way, the linux machine has double cores and double processes). That means if there are two tasks(both u...
How to un-escape a backslash-escaped string?
...s a backslash-escaped version of another string. Is there an easy way, in Python, to unescape the string? I could, for example, do:
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Is there a difference between using a dict literal and a dict constructor?
...d BUILD_MAP and STORE_MAP opcodes rather than generic CALL_FUNCTION:
> python2.7 -m timeit "d = dict(a=1, b=2, c=3, d=4, e=5)"
1000000 loops, best of 3: 0.958 usec per loop
> python2.7 -m timeit "d = {'a':1, 'b':2, 'c':3, 'd':4, 'e':5}"
1000000 loops, best of 3: 0.479 usec per loop
> pyt...
Getting the exception value in Python
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For python2, It's better to use e.message to get the exception message, this will avoid possible UnicodeDecodeError. But yes e.message will be empty for some kind of exceptions like OSError, in which case we can add a exc_info=Tr...
Very large matrices using Python and NumPy
...oing SQL-like GROUP BY aggregation at 1,000,000 rows/second. Not bad for a Python-based solution!
Accessing the data as a NumPy recarray again is as simple as:
data = table[row_from:row_to]
The HDF library takes care of reading in the relevant chunks of data and converting to NumPy.
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Python string prints as [u'String']
...d as Unicode to bytes in most cases: you should print Unicode directly in Python: print(', '.join([u'ABC' , u'...']))
– jfs
Jun 12 '16 at 17:20
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App Inventor 2开发计步器与定位器 - App Inventor 2 中文网 - 清泛IT论坛，有思想、有深度
...时，数据依然存储在手机中。【参二】健身宝程序及资源下载AI伴侣最新版（广州版）健身宝（简版)（请右键选择链接另存为）健身宝（扩展版）（请右键选择链接另存为）【参三】我的车在哪儿 1、位置传感器
App Inventor为...
Using python “with” statement with try-except block
Is this the right way to use the python "with" statement in combination with a try-except block?:
4 Answers
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