Nyahua

run a python program in background

nohup $python program.py &

disable ssh timeout

first: sudo nano /etc/ssh/sshd_config
add the following lines:

TCPKeepAlive no

using the csv module from the standard library and the open method to avoid leaving the file open.

The key point is using 'a' for appending when you open the file.

import csv   
fields=['first','second','third']
with open(r'name', 'a') as f:
    writer = csv.writer(f)
    writer.writerow(fields)

mongodump --db=<old_db_name> --collection=<collection_name> --out=data_directory/
tar -zcvf archive.tar.gz data_directory/ 

mongorestore --db=<new_db_name> --collection=<collection_name> data/<db_name>/<collection_name>.bson

import pymongo, json

def db_connection(db_name, collection_name):
 client = pymongo.MongoClient('mongodb://localhost:27017/')

SQL to MongoDB Mapping Chart

SQL to MongoDB Mapping Chart¶

In addition to the charts that follow, you might want to consider the Frequently Asked Questions section for a selection of common questions about MongoDB.

Executables¶

The following table presents the MySQL/Oracle executables and the corresponding MongoDB executables.

SQL to MongoDB Mapping Chart

SQL to MongoDB Mapping Chart¶

In addition to the charts that follow, you might want to consider the Frequently Asked Questions section for a selection of common questions about MongoDB.

Executables¶

The following table presents the MySQL/Oracle executables and the corresponding MongoDB executables.

	import folium

	ref_html = r'<a href="http://www.shenyang.gov.cn/" target="_blank"> I am here </a>'
	pop_html = folium.Popup(folium.Html(ref_html, script=True))

	map_1 = folium.Map(location=[41.8057, 123.4315], zoom_start=12,
	tiles='Stamen Terrain')
	folium.Marker(
	location = [41.8057, 123.4315],
	popup = pop_html).add_to(map_1)

	import openpyxl
	import numpy as np
	import pandas as pd

	def get_column_letter(col_idx):
	"""Convert a column number into a column letter (3 -> 'C')
	Right shift the column col_idx by 26 to find column letters in reverse
	order. These numbers are 1-based, and can be converted to ASCII
	ordinals by adding 64.
	"""

	import sqlite3, os

	def vacuum(db_name):
	print("Filesize of {} before vaccum is {:,d} bytes.".
	format(db_name, os.stat(db_name).st_size)
	)
	conn = sqlite3.connect(db_name)
	isolation = conn.isolation_level
	print(isolation)
	conn.isolation_level = None

	def dict_inter(dict_in, flds):
	dict_out = {
	key: dict_in[key] for key in flds if key in dict_in.keys()
	}
	return dict_out

	def dict_diff(dict_in, flds):
	dict_out = {
	key: dict_in[key] for key in dict_in.keys() if key not in flds
	}