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How to implement the --verbose or -v option into a script?
...nt, and it'll only get defined if the condition is true!)
If you're using Python 3, where print is already a function (or if you're willing to use print as a function in 2.x using from __future__ import print_function) it's even simpler:
verboseprint = print if verbose else lambda *a, **k: None
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Convert nested Python dict to object?
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Update: In Python 2.6 and onwards, consider whether the namedtuple data structure suits your needs:
>>> from collections import namedtuple
>>> MyStruct = namedtuple('MyStruct', 'a b d')
>>> s = MyStruct(a=1, ...
What are some good Python ORM solutions? [closed]
...ally a JavaScript front-end from the client-side (browser) that talks to a Python web service on the back-end. So, I really need something fast and lightweight on the back-end that I can implement using Python that then speaks to the PostgreSQL DB via an ORM (JSON to the browser).
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Using Python String Formatting with Lists
I construct a string s in Python 2.6.5 which will have a varying number of %s tokens, which match the number of entries in list x . I need to write out a formatted string. The following doesn't work, but indicates what I'm trying to do. In this example, there are three %s tokens and the list ...
UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position 20: ordinal not in rang
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You need to read the Python Unicode HOWTO. This error is the very first example.
Basically, stop using str to convert from unicode to encoded text / bytes.
Instead, properly use .encode() to encode the string:
p.agent_info = u' '.join((agent_c...
How to “test” NoneType in python?
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Why this works?
Since None is the sole singleton object of NoneType in Python, we can use is operator to check if a variable has None in it or not.
Quoting from is docs,
The operators is and is not test for object identity: x is y is true if and only if x and y are the same object. x is not...
Check whether a path is valid in Python without creating a file at the path's target
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Call the is_path_exists_or_creatable() function defined below.
Strictly Python 3. That's just how we roll.
A Tale of Two Questions
The question of "How do I test pathname validity and, for valid pathnames, the existence or writability of those paths?" is clearly two separate questions. Both are...
How do I save and restore multiple variables in python?
...created here...
# Saving the objects:
with open('objs.pkl', 'w') as f: # Python 3: open(..., 'wb')
pickle.dump([obj0, obj1, obj2], f)
# Getting back the objects:
with open('objs.pkl') as f: # Python 3: open(..., 'rb')
obj0, obj1, obj2 = pickle.load(f)
If you have a lot of data, you can...
Return first N key:value pairs from dict
...urn list(islice(iterable, n))
See it working online: ideone
Update for Python 3.6
n_items = take(n, d.items())
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How can I create a copy of an object in Python?
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How can I create a copy of an object in Python?
So, if I change values of the fields of the new object, the old object should not be affected by that.
You mean a mutable object then.
In Python 3, lists get a copy method (in 2, you'd use a slice to make a copy):
&g...