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Is there a way to perform “if” in python's lambda
In python 2.6 , I want to do:
16 Answers
16
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Why doesn't Python have a sign function?
I can't understand why Python doesn't have a sign function. It has an abs builtin (which I consider sign 's sister), but no sign .
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Writing a list to a file with Python
...', 'w') as f:
for item in my_list:
f.write("%s\n" % item)
In Python 2, you can also use
with open('your_file.txt', 'w') as f:
for item in my_list:
print >> f, item
If you're keen on a single function call, at least remove the square brackets [], so that the strings...
Truncating floats in Python
....partition('.')
return '.'.join([i, (d+'0'*n)[:n]])
This is valid in Python 2.7 and 3.1+. For older versions, it's not possible to get the same "intelligent rounding" effect (at least, not without a lot of complicated code), but rounding to 12 decimal places before truncation will work much of...
Convert python datetime to epoch with strftime
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If you want to convert a python datetime to seconds since epoch you could do it explicitly:
>>> (datetime.datetime(2012,04,01,0,0) - datetime.datetime(1970,1,1)).total_seconds()
1333238400.0
In Python 3.3+ you can use timestamp() instead:...
Get: TypeError: 'dict_values' object does not support indexing when using python 3.2.3 [duplicate]
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In Python 3, dict.values() (along with dict.keys() and dict.items()) returns a view, rather than a list. See the documentation here. You therefore need to wrap your call to dict.values() in a call to list like so:
v = list(d.va...
How do I use method overloading in Python?
I am trying to implement method overloading in Python:
15 Answers
15
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Python `if x is not None` or `if not x is None`?
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There's no performance difference, as they compile to the same bytecode:
Python 2.6.2 (r262:71600, Apr 15 2009, 07:20:39)
>>> import dis
>>> def f(x):
... return x is not None
...
>>> dis.dis(f)
2 0 LOAD_FAST 0 (x)
3 LOAD_CONST...
Python Graph Library [closed]
I'm writing a python application that will make heavy use of a graph data structure. Nothing horribly complex, but I'm thinking some sort of graph/graph-algorithms library would help me out. I've googled around, but I don't find anything that particularly leaps out at me.
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Python's time.clock() vs. time.time() accuracy?
Which is better to use for timing in Python? time.clock() or time.time()? Which one provides more accuracy?
16 Answers
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