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Python and pip, list all versions of a package that's available?
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170
(update: As of March 2020, many people have reported that yolk, installed via pip install yolk3k...
How to replace NaN values by Zeroes in a column of a Pandas Dataframe?
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807
I believe DataFrame.fillna() will do this for you.
Link to Docs for a dataframe and for a Seri...
[since C++11] std::array的使用 - C/C++ - 清泛网 - 专注C/C++及内核技术
...算符和初始化列表：
array<int, 3> a = {1, 2, 3};
array<int, 100> b = {1, 2, 3}; // a[0] ~ a[2] = 1, 2, 3; a[3] ~ a[99] = 0, 0, 0 ... 0;
array<int, 3> c; // c[0] ~ c[2] 未初始化，是垃圾值.
assignment
形式
说明
c = other
把ot...
Plot a legend outside of the plotting area in base graphics?
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10 Answers
10
Active
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Regular expression for matching HH:MM time format
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Your original regular expression has flaws: it wouldn't match 04:00 for example.
This may work better:
^([0-1]?[0-9]|2[0-3]):[0-5][0-9]$
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How to convert floats to human-readable fractions?
Let's say we have 0.33 , we need to output 1/3 .
If we have 0.4 , we need to output 2/5 .
26 Answers
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Why doesn't Python have a sign function?
...cause they didn't agree on what it should return in all the edge cases (+/-0, +/-nan, etc)
So they decided to implement only copysign, which (although more verbose) can be used to delegate to the end user the desired behavior for edge cases - which sometimes might require the call to cmp(x,0).
I...
Outline effect to text
...stroked text:
.strokeme {
color: white;
text-shadow: -1px -1px 0 #000, 1px -1px 0 #000, -1px 1px 0 #000, 1px 1px 0 #000;
}
&lt;div class="strokeme"&gt;
This text should have a stroke in some browsers
&lt;/div&gt;
I have made a demo for you here
And a hovered example is avai...
What is a good regular expression to match a URL? [duplicate]
...you want to ensure URL starts with HTTP/HTTPS:
https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&amp;//=]*)
If you do not require HTTP protocol:
[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&amp;//=]*)
To try this out s...
Getting the array length of a 2D array in Java
... };
System.out.println(foo.length); //2
System.out.println(foo[0].length); //3
System.out.println(foo[1].length); //4
}
Column lengths differ per row. If you're backing some data by a fixed size 2D array, then provide getters to the fixed values in a wrapper class.
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