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Multiple aggregations of the same column using pandas GroupBy.agg()
... 34.0 6.0
Lastly, if your column names aren't valid python identifiers, use a dictionary with unpacking:
df.groupby('kind')['height'].agg(**{'max height': 'max', ...})
Pandas < 0.25
In more recent versions of pandas leading upto 0.24, if using a dictionary for specify...
Why shouldn't I use “Hungarian Notation”?
...er's job also, but that would incur a huge overhead for dynamic languages (Python, Ruby, PHP or Javascript).
– too much php
Dec 29 '08 at 3:45
22
...
Truly understanding the difference between procedural and functional
... style there is pretty hard to read compared the the "functional style" in python: def odd_words(words): return [x for x in words if odd(len(x))]
– boxed
Dec 12 '13 at 9:11
...
What is the difference between related SQLite data-types like INT, INTEGER, SMALLINT and TINYINT?
...'t have to handle such non-zero numeric fields specially. An example using Python's sqlite3 module would be,
conn_or_cursor.execute(
"INSERT INTO table VALUES (" + ",".join("?" * num_values) + ")",
str_value_tuple) # no need to convert some from str to int/float
In the above example, ...
Rename specific column(s) in pandas
...lse x, axis=1)
Index.str.replace
Similar to replace method of strings in python, pandas Index and Series (object dtype only) define a ("vectorized") str.replace method for string and regex-based replacement.
df.columns = df.columns.str.replace('gdp', 'log(gdp)')
df
y log(gdp) cap
0 x ...
How can I parse a CSV string with JavaScript, which contains comma in data?
... are first presented in native regular expressions syntax (expressed using Python's handy r'''...''' raw-multi-line-string syntax).
First here is a regular expression which validates that a CVS string meets the above requirements:
Regular expression to validate a "CSV string":
re_valid = r"""
# Vali...
Does PostgreSQL support “accent insensitive” collations?
...critics known to Unicode, and expand ligatures correctly (Thomas
Munro, Léonard Benedetti)
Bold emphasis mine. Now we get:
SELECT unaccent('Œ Æ œ æ ß');
unaccent
----------
OE AE oe ae ss
Pattern matching
For LIKE or ILIKE with arbitrary patterns, combine this with the module pg_trgm ...
How to create the most compact mapping n → isprime(n) up to a limit N?
...orithm I usually implement (easy to understand and code) is as follows (in Python):
def isprime(n):
"""Returns True if n is prime."""
if n == 2:
return True
if n == 3:
return True
if n % 2 == 0:
return False
if n % 3 == 0:
return False
i = 5
...
Git commits are duplicated in the same branch after doing a rebase
..." onto "Develop-branch"
Push force of changes on "Feature-branch"
As conséquences of this workflow, duplication of all commits of "Feature-branch" since previous rebase... :-(
The issue was due to the pull of changes of child branch before rebase. Git default pull configuration is "merge". This ...
Is it possible to specify your own distance function using scikit-learn K-Means Clustering?
... enough);
in particular, what are your N, dim, k, metric ?
#!/usr/bin/env python
# kmeans.py using any of the 20-odd metrics in scipy.spatial.distance
# kmeanssample 2 pass, first sample sqrt(N)
from __future__ import division
import random
import numpy as np
from scipy.spatial.distance import cdi...