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# create a virtual env called myvirtualenv
virtualenv myvirtualenv

# activate the virtual environment and install everything from requirements
source myvirtualenv/bin/activate
pip install -r requirements.txt

# check which venv you are in
which python

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# When working with R files created using locales that are not installed, this is how you generate new ones. 
# Works on Ubuntu 20.04.4 LTS

# prints out locales that are already created and accessible.
locale -a 

# generate a new one, for example French
locale-gen fr

# Update the locales so that R can access them

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name: data-visualization

dependencies:
  - python=3.9.7
  - pandas
  - numpy
  - matplotlib
  - seaborn
  - pip
  - pip:

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import numpy as np

## Make a table of counts of each value in a numpy array.
# This returns the unique values and their counts in a numpy array.
x = np.array([1, 1, 1, 2, 2, 2, 7, 14, 2, 1])
unique, counts = np.unique(x, return_counts=True)

print(np.asarray((unique, counts)).T)   # Use transpose for better visual

## Sort it

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# Manual garbage collection due to limited RAM - useful in Kaggle competitions
import sys
for i in dir(): 
    if sys.getsizeof(eval(i)) > 10000: 
        print("the size of {} is:".format(i), sys.getsizeof(eval(i))/1e+9)

import gc
del train   # delete a data frame
gc.collect()   # manual garbage collection

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/* Basic viewing the structure commands */
\c database_name --connect to a database.
\dt --view the tables. this filters out non-table relations.
\d  --view the tables. Includes non-table relations.
\d tablename --view the columns of the table.


/* Create a table and import from a csv into that table. */
CREATE TABLE employees (
  id SERIAL, 

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#!/bin/sh 

# Where I am storing useful sed commands for later use. 

# Removing characters from a csv or text file. This removes a double-quote.
sed 's/"//g' filename.csv 
sed 's/"//g' filename.csv > filename_new.csv

# Not sed, but using cut to remove columns of a csv file.
# This takes a pipe-delimited file and removes columns 2, 3, and 4.

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# From this problem on leetcode. 

# https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary/

# Given an array of unique integers salary where salary[i] is the salary of the employee i.

# Return the average salary of employees excluding the minimum and maximum salary.

# Example: 
# Input: salary = [4000,3000,1000,2000]

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/* 
Given 2 tables in a MySQL database, Employee and Department, find the employees (including ties) with the highest 
salaries for each department. 

Employee table: 
Id (auto incremented integer)
Name (Varchar, employee name)
DepartmentId (integer and key to Department table)
Salary (Integer)