5.11.2019 Python

>>> break
SyntaxError: 'break' outside loop
>>> continue
SyntaxError: 'continue' not properly in loop
>>> a = [6.343, 333, 333, 1, 44 , 2 , 4 ,5, 66]
>>> a
[6.343, 333, 333, 1, 44, 2, 4, 5, 66]
>>> a.count(333)
2
>>> a.count()
Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    a.count()
TypeError: count() takes exactly one argument (0 given)
>>> a.append(
12)
>>> a.insert(2, 100)
>>> a
[6.343, 333, 100, 333, 1, 44, 2, 4, 5, 66, 12]
>>> a.index(333)
1
>>> a.remove(333)
>>> a
[6.343, 100, 333, 1, 44, 2, 4, 5, 66, 12]
>>> while a:
    x = a.pop()
    print(x, end=' ')


12 66 5 4 2 44 1 333 100 6.343
>>> a
[]
>>> a = [6.343, 333, 333, 1, 44 , 2 , 4 ,5, 66]
>>> del a[1]
>>> a
[6.343, 333, 1, 44, 2, 4, 5, 66]
>>> a.extend([1,2])
>>> a
[6.343, 333, 1, 44, 2, 4, 5, 66, 1, 2]
>>> a.reverse()
>>> a
[2, 1, 66, 5, 4, 2, 44, 1, 333, 6.343]
>>> a.sort()
>>> a
[1, 1, 2, 2, 4, 5, 6.343, 44, 66, 333]
>>> b = ['dasda', 'dsds' , 'aaa', 'bf']
>>> b.sort()
>>> b
['aaa', 'bf', 'dasda', 'dsds']
>>> c = [[1,2], [-3,4], [3,3]]
>>> c.sort()
>>> c
[[-3, 4], [1, 2], [3, 3]]
----------------------------------------------

a = []
for i in range(10):
    a.append(i*i)

print(a)

----------------------------------------------

def squared(b):
    a = []
    for i in b:
        a.append(i*i)
    return a

c = squared([1,4,8,10])

print(c)

------------------------------------------------

[1, 16, 64, 100]
>>> a
[1, 4, 8, 10]
>>> c
[1, 16, 64, 100]
>>> [a**2 for a in range(5)]
[0, 1, 4, 9, 16]
>>> [a**2 for a in c]
[1, 256, 4096, 10000]
>>> from math import pi
>>> round(pi, 2)
3.14
>>> round(pi, 3)
3.142
>>> [round(pi, i) for i in range(1,9)]
[3.1, 3.14, 3.142, 3.1416, 3.14159, 3.141593, 3.1415927, 3.14159265]


------------------------------------------------------------------------

a=[1,4,8,10]
sq=[]
for i in a:
    if i > 0:
        sq.append(i*i)

print(sq)
------------------ lub ------------------

[1, 16, 64, 100]
>>> [x**2 for x in a if x > 0]
[1, 16, 64, 100]

---------------------------------------------------------------------------

wyrazy = ['pawel', 'pajor', 'bolek', 'gaborek']

ini = [x[:2] for x in wyrazy]

# bez y na drugim miejscu
# ini = [x[:2] for x in wyrazy if x[1] != 'y']

print(ini)

-------------------------------------

lista1 = [1,2,3]
lista2 = [3,1,4,3]

nowa = []

for x in lista1:
    for y in lista2:
        if (x != y):
            nowa.append([x,y])

print(nowa)


pary2 = [[x,y] for x in lista1 for x in lista2 if x != y]
print(pary2)


------------------------------------------------------------------

v = [-4, -2, 0, 2, 4]

# lista podwojonych wartosci obiektow z tej listy

c = [2*i for i in v]

# Tylko nieujemne wartosci z v

x = [i for i in v if i > 0]

#  wartosci bezwzgledne

z = [abs(i) for i in v]

# lista [el, kwadrat el]

b = [[i, i**2] for i in v]

print(c)
print(x)
print(z)
print(b)

-------------------------------------------------------

# chcemy spłaszczyć listę

vec = [[1,2,3],
       [4,5,6],
       [7,8,9]]

vec1 = []

for i, x in enumerate(vec):
    for z, y in enumerate(x):
      vec1.append(vec[i][z])

vec2 = [ y for x in vec for y in x ]

print(vec1)
print(vec2)

----------------------------------------------------------

>>> 2 * [1,2,3]
[1, 2, 3, 1, 2, 3]
>>> 15 * [0]
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

------------------------------------------------------------

[15*[i] for i in range(10)]

------------------------------------------------------------

[3*[5*[0]]]

------------------------------------------------------------

a = 3 * [5 * [0]]
[[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]
>>> a[1][2] = 100
>>> a
[[0, 0, 100, 0, 0], [0, 0, 100, 0, 0], [0, 0, 100, 0, 0]]
------------------------------------------------------------