大约有 47,000 项符合查询结果（耗时：0.0595秒） [XML]
Pandas: create two new columns in a dataframe with values calculated from a pre-existing column
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119
I'd just use zip:
In [1]: from pandas import *
In [2]: def calculate(x):
...: return ...
Assign pandas dataframe column dtypes
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Since 0.17, you have to use the explicit conversions:
pd.to_datetime, pd.to_timedelta and pd.to_numeric
(As mentioned below, no more "magic", convert_objects has been deprecated in 0.17)
df = pd.DataFrame({'x': {0: 'a', 1: 'b'}, ...
Update multiple rows in same query using PostgreSQL
...izable:
update test as t set
column_a = c.column_a
from (values
('123', 1),
('345', 2)
) as c(column_b, column_a)
where c.column_b = t.column_b;
You can add as many columns as you like:
update test as t set
column_a = c.column_a,
column_c = c.column_c
from (values
('12...
Get type of all variables
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110
You need to use get to obtain the value rather than the character name of the object as return...
Add missing dates to pandas dataframe
...u could use Series.reindex:
import pandas as pd
idx = pd.date_range('09-01-2013', '09-30-2013')
s = pd.Series({'09-02-2013': 2,
'09-03-2013': 10,
'09-06-2013': 5,
'09-07-2013': 1})
s.index = pd.DatetimeIndex(s.index)
s = s.reindex(idx, fill_value=0)
p...
Why is parenthesis in print voluntary in Python 2.7?
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107
In Python 2.x print is actually a special statement and not a function*.
This is also why it ...
Most efficient way of making an if-elif-elif-else statement when the else is done the most?
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100
The code...
options.get(something, doThisMostOfTheTime)()
...looks like it ought to be fast...
How to use JavaScript variables in jQuery selectors?
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edited Jun 25 '15 at 5:31
answered May 5 '11 at 2:10
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Add to Array jQuery
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301
For JavaScript arrays, you use push().
var a = [];
a.push(12);
a.push(32);
For jQuery objects...
Python Dictionary to URL Parameters
... key-value pairs, and converts it into a form suitable for a URL (e.g., key1=val1&key2=val2).
If you are using Python3, use urllib.parse.urlencode()
If you want to make a URL with repetitive params such as: p=1&p=2&p=3 you have two options:
>>> import urllib
>>> a = ...