Python3 cheatsheet
I rarely use python, when I do, I always forget about the basics. Here you can find a list of the stuff I need to remind myself time and time again.
Table of contents
Loops
Lists
for animal in ["dog", "cat", "mouse"]:
Dictionary
for key, value in {"one": 1, "two": 2, "three": 3}.items():
Lists/Arrays
l = [1, 2, 3]
length = len(l)
first_element = l[0]
Algebraic structures
- map
x = map(a_function, iterable)
Sorting
- Manipulates the list
l.sort(key=lambda k: k[0], reverse=True)
. - Returns a new list, the original list remains untouched
sorted(l, key=lambda k: k[0], reverse=True)
Functions
def named_function(x = 1, y = 2):
return x, y # returns a tuple
x, y = named_function()
Strings
- substring
my_string[0:5]
- contains substring -
'substring' in my_string
- parse
string(a_number)
- interpolation
f'Hello {who}!'
where who is a variable - join
'-'.join(list)
Regular expression
import re
match = re.search(r"\w+/[\d]+/([\d]+)", searchString)
full_match = match.group(0)
group1 = match.group(1)
Types
Parse
- float(someString)
- int(someString)
Type Check
isinstance(test_string, str)
Random
import random
random.random()
Sleep
import time
time.sleep(2.4)