Antonio Kam anto [at] berkeley [dot] edu
anto [at] berkeley [dot] edu
is_prime
n - 1
def is_prime(n): def helper(i): if i == 1: return True elif i < 1 or n % i == 0: # i < 1 necessary for if you enter n = 1 return False return helper(i - 1) return helper(n - 1)
map
filter
reduce
for
teaching.rouxl.es
[1, "hello", [2, "hi"]]
In general, to create a list, you wrap something in square brackets
[1, 2, 3]
Syntax is lst[<start index>:<end index>:<step>]; this creates a copy of all or part of your list (will be important later)
lst[<start index>:<end index>:<step>]
start index
end index
step
lst = [3, 4, 5] lst[:] # Makes a copy; returns [3, 4, 5] lst[1:] # [4, 5] lst[::-1] # [5, 4, 3] lst[::2] # [3, 5]
for <variable> in <sequence>: [body of for loop]
Example:
lst = [3, 4, 5] for elem in lst: print(elem)
Very similar to for loops, but can be done in 1 line!
[<expression> for <variable> in <sequence> [if <condition>]] lst = [3, 2, 1] [x * 2 for x in lst if x < 3] # [4, 2] [x * 2 for x in [3, 2, 1]] # [6, 4, 2]
links.rouxl.es/disc
keys
values
{}
{key: value}
Demo:
pokemon = {'pikachu': 25, 'dragonair': 148, 25: 'hello'} pokemon['pikachu'] # 25 pokemon['hello'] = 'hi' pokemon # {'pikachu': 25, 'dragonair': 148, 25: 'hello', 'hello': 'hi'}
links.rouxl.es/feedback
Thanks for coming!
Please give me feedback on what to improve!