Lists
packages = ['numpy','pandas','scipy']
for i in packages:
print(i)
import pandas as pd
list_keys = ['a','b']
list_values = [['x','y'],[1,2]]
all = list(zip(list_keys, list_values))
> all
> [('a',['x','y']),('b',[1,2])]
[i for i in range(5) if i > 2]
> [3, 4]
[s.upper() for s in ['hallo','aarde']]
> ['HALLO','AARDE']
Dictionaries
d = { 'appel': 1, 'peer': 2, 'kokos': 3 }
d['banaan'] = 4
> d
> { 'appel': 1, 'peer': 2, 'kokos': 3, 'banaan': 4 }
d= {'een': 1, 'twee': 2, 'drie': 3, 'vier': 4}
> d['twee']
> 2
Arrays numpy
import numpy as np
arr = np.array([1,2,3])
> type(arr)
> numpy.ndarray
import numpy as np
x = np.array([1, 2, 3, 4])
y = 3
> x == y
> array([False, False, True, False])
import numpy as np
arr = np.array([1, 2, 3, 4, 5])
> arr[arr >3]
> [4, 5]
Iterators
w = 'python'
w_iterator = iter(w)
> next(w_iterator)
> 'p'
Lambda Function
f = lambda x, y: x * y
> f(3,3)
> 9
Functions
def add(a, b= 1):
return a + b
> add(14)
> 15
def double_number(n):
return n * 2
double_number(4)
def subtract(n, p=1):
return n - p
> subtract(4)
> 3
def to_int(x):
try:
return int(x)
except ValueError:
print("No conversion possible")
> to_int("")
> No conversion possible
def f():
"""returns two"""
return 2
> help(f)
Help on function f in module __main__:
f()
returns two
from pytest import *
import numpy as np
def test_addition():
assert 1 + 1 == 2
> show_test_output(test_addition)
====== test session starts ========
platform linux -- Python 3.6, ...
rootdir: /tmp/tmpxxxx
collected 1 item
test_file.py .
====== 1 passed in 0.01 seconds ==
Object Oriented Programming
class Snoep:
smaak = 'zoet'
def __init__(self, name):
self.name = name
> c = Snoep('Chocolade')
> c.name
> 'Chocolade'
class hond:
def woef(self):
return 'woef'
> milou = hond()
> milou.woef()
> 'woef'