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pandas read_csv and filter columns with usecols
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Fastest way to replace NAs in a large data.table
...le) # v1.6.6
require(gdata) # v2.8.2
set.seed(1)
dt1 = create_dt(2e5, 200, 0.1)
dim(dt1)
[1] 200000 200 # more columns than Ramnath's answer which had 5 not 200
f_andrie = function(dt) remove_na(dt)
f_gdata = function(dt, un = 0) gdata::NAToUnknown(dt, un)
f_dowle = function(dt) { ...
For loop example in MySQL
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145
drop table if exists foo;
create table foo
(
id int unsigned not null auto_increment primary key...
Pandas get topmost n records within each group
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Did you try df.groupby('id').head(2)
Ouput generated:
>>> df.groupby('id').head(2)
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Python: Get the first character of the first string in a list?
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answered Aug 18 '11 at 13:25
agfagf
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Convert list of dictionaries to a pandas DataFrame
... edited Jul 22 at 17:24
cs95
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answered Dec 17 '13 at 15:35
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How to convert list of tuples to multiple lists?
...n zip() will almost do what you want:
>>> zip(*[(1, 2), (3, 4), (5, 6)])
[(1, 3, 5), (2, 4, 6)]
The only difference is that you get tuples instead of lists. You can convert them to lists using
map(list, zip(*[(1, 2), (3, 4), (5, 6)]))
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How to drop rows of Pandas DataFrame whose value in a certain column is NaN
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eumiroeumiro
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