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Python constructor and default value [duplicate]
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This is considered the Pythonic way, but I prefer krousey's way because "special cases aren't special enough".
– Karl Knechtel
Jan 30 '11 at 9:44
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Complex numbers usage in python [closed]
I'm a math newbie. Now I'm getting deeper into Python data types. I can't understand how to use a complex number. Please give me examples of usage of complex numbers in Python.
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Why doesn't calling a Python string method do anything unless you assign its output?
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This is because strings are immutable in Python.
Which means that X.replace("hello","goodbye") returns a copy of X with replacements made. Because of that you need replace this line:
X.replace("hello", "goodbye")
with this line:
X = X.replace("hello", "goodbye"...
How do I write a Python dictionary to a csv file? [duplicate]
...want to check out the with statement for opening files. It's not only more pythonic and readable but handles closing for you, even when exceptions occur.
Example with these changes made:
import csv
my_dict = {"test": 1, "testing": 2}
with open('mycsvfile.csv', 'wb') as f: # Just use 'w' mode in...
Calling filter returns [duplicate]
I am learning the concept of filters in Python. I am running a simple code like this.
2 Answers
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Python if-else short-hand [duplicate]
I want to do the following in python:
2 Answers
2
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Display number with leading zeros
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In Python 2 (and Python 3) you can do:
print "%02d" % (1,)
Basically % is like printf or sprintf (see docs).
For Python 3.+, the same behavior can also be achieved with format:
print("{:02d}".format(1))
For Python 3.6...
Union of dict objects in Python [duplicate]
How do you calculate the union of two dict objects in Python, where a (key, value) pair is present in the result iff key is in either dict (unless there are duplicates)?
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Class method differences in Python: bound, unbound and static
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In Python, there is a distinction between bound and unbound methods.
Basically, a call to a member function (like method_one), a bound function
a_test.method_one()
is translated to
Test.method_one(a_test)
i.e. a call to ...
Python __str__ and lists
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Calling string on a python list calls the __repr__ method on each element inside. For some items, __str__ and __repr__ are the same. If you want that behavior, do:
def __str__(self):
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def __repr__(self):
return self.__str__()
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