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How to count the number of occurrences of an element in a List
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341
I'm pretty sure the static frequency-method in Collections would come in handy here:
int occu...
How to filter a dictionary according to an arbitrary condition function?
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434
Nowadays, in Python 2.7 and up, you can use a dict comprehension:
{k: v for k, v in points.ite...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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using awk with column value conditions
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132
If you're looking for a particular string, put quotes around it:
awk '$1 == "findtext" {print ...
get list from pandas dataframe column
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534
Pandas DataFrame columns are Pandas Series when you pull them out, which you can then call x.to...
Why does base64 encoding require padding if the input length is not divisible by 3?
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3 Answers
3
Active
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C#位运算符（C#按位与、按位或 等） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...如：10010001（二进制）&11110000等于10010000（二进制）。
3、位逻辑或运算
位逻辑或运算将两个运算对象按位进行或运算。或运算的规则是：1或1等1，1或0等于1，
0或0等于0。比如10010001（二进制）| 11110000（二进制）等于11110001...
How can I convert a dictionary into a list of tuples?
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363
>>> d = { 'a': 1, 'b': 2, 'c': 3 }
>>> d.items()
[('a', 1), ('c', 3), ('b', ...
filter items in a python dictionary where keys contain a specific string
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183
How about a dict comprehension:
filtered_dict = {k:v for k,v in d.iteritems() if filter_string ...
Change the name of a key in dictionary
...elete dictionary[old_key].
>>> dictionary = { 1: 'one', 2:'two', 3:'three' }
>>> dictionary['ONE'] = dictionary.pop(1)
>>> dictionary
{2: 'two', 3: 'three', 'ONE': 'one'}
>>> dictionary['ONE'] = dictionary.pop(1)
Traceback (most recent call last):
File "<inp...