Python 3 Snippets

int

i = 123

str

s = ''
s = str(200) + ' calories'
len('ABCD')                # 4

name = 'John'
age = 8
s = f'{name} is {age} years old.'
s = f'{age:03d}'                  # 008

if 'apple' == 'apple':
	print('Same')

dict

d = {"JAN": 1, "FEB": 2, "MAR": 3}
d["JAN"]   # 1

list

d = []
d = [1, 2, 3]

d.append(4)

d[-1] = 8        # last element

tuple

e = ('abcd', 123, 456, 'efgh')
e[0]    # abcd

If Else

if a == 100 and b == 'banana':
	#
elif row[0] in MONTHS:
	#
else:
	#

For Loop

ages = [1, 2, 3]


for age in ages:
	print(age)


for idx, age in enumerate(ages):
	if idx == 3:
		continue

Function

def add(a, b):
	return a + b


c = add(1, 2)


def aaa(amount=0, description=''):
	date = date

SQLite

conn = sqlite3.connect('school.db')
c = conn.cursor()


s = [('Tom', 22), ('Bob', 33), ('Sam', 44)]
c.executemany('''INSERT INTO students(name,age) 
                 VALUES (?,?)''', s)


conn.commit()
conn.close()

CSV (Excel)

a = []


with open('list.csv', newline='') as csvfile:
	# Skip first line
	next(csvfile)
	
	reader = csv.reader(csvfile)
	for row in reader:
		a.append([row[0], row[1]])

Unix Timestamp

import time

timestamp = time.time()

Date

from datetime import date

d = date(2020, 12, 31)
d.isoformat() # '2020-12-31'
d.year        # 2020
d.month       # 12

Class

class Apple:
	def __init__(self, weight=100):
		self.weight = weight
		
	def __repr__(self):
		return 'Weight: ' + str(self.weight)


a = Apple()
a.weight           # 100
print(a)           # Weight: 100
'Apple: ' + str(a) # 'Apple: Weight: 100'

Shell (cmd)

import subprocess

subprocess.run('ping 127.0.0.1', shell=True)
subprocess.run('"C:\\Program Files\\test.exe" -i abc',
    shell=True)