In [5]:
print(z)
z = 0

<cell>1: error: Name "z" is used before definition  [used-before-def]

0
In [6]:
ct = 0
In [18]:
print(ct)
ct = ct + 1

<cell>1: error: Cannot determine type of "ct"  [has-type]
<cell>1: error: Name "ct" is used before definition  [used-before-def]
<cell>2: error: Cannot determine type of "ct"  [has-type]

8
In [24]:
from math import sqrt

def hypotenuse(a, b):
    # print("a was", a)
    return sqrt(a**2 + b**2)

hypotenuse(3, 4)
Out[24]:
5.0
In [27]:
def pythagoras(a, b):
    """
    Return the length of the hypotenuse of a
    right triangle with side lengths a and b.
    """
    return sqrt(a**2 + b**2)

help(pythagoras)

Help on function pythagoras in module __main__:

pythagoras(a, b)
    Return the length of the hypotenuse of a
    right triangle with side lengths a and b.
In [29]:
def sillystring():
    return """
    Hello world!
    """ # This is not a docstring

"""
This
is
a multi-line
comment
"""

print(sillystring())
help(sillystring)

    Hello world!
    
Help on function sillystring in module __main__:

sillystring()
In [ ]:
def pythagoras(a, b):
    sqrt(a**2 + b**2)
In [31]:
def hypotenuse(a, b):
    return sqrt(a**2 + b**2)

print(hypotenuse(3, 4))
print(5)

5.0
5
In [36]:
print(float(42))
print(int(41.999))
print(round(41.999))

print(round(41.912, 2))

42.0
41
42
41.91
In [39]:
def hypotenuse(a: float, b: float) -> str:
    return sqrt(a**2 + b**2)

print(hypotenuse(3, 4))

<cell>2: error: Incompatible return value type (got "float", expected "str")  [return-value]

5.0
In [44]:
x = print("Hello")
print(x)
print(x / 10)

<cell>3: error: Unsupported operand types for / ("None" and "int")  [operator]

Hello
None

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Input In [44], in <cell line: 3>()
      1 x = print("Hello")
      2 print(x)
----> 3 print(x / 10)

TypeError: unsupported operand type(s) for /: 'NoneType' and 'int'
In [46]:
def divide(a: float, b: float) -> float:
    return a / b

print(divide(3, 4))
print(divide(3, 0))

0.75

---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
Input In [46], in <cell line: 5>()
      2     return a / b
      4 print(divide(3, 4))
----> 5 print(divide(3, 0))

Input In [46], in divide(a, b)
      1 def divide(a: float, b: float) -> float:
----> 2     return a / b

ZeroDivisionError: division by zero
In [50]:
def hypotenuse(a: float, b: float) -> float:
    return sqrt(a**2 + b**2)

assert hypotenuse(3, 4) == 5, "3-4-5 triangle"
# WARNING: Don't use == for floats!
In [52]:
def zeroDotThreeMinusZeroDotTwo():
    return 0.3-0.2

print(zeroDotThreeMinusZeroDotTwo())
assert zeroDotThreeMinusZeroDotTwo() == 0.1, "Math too simple to fail"

0.09999999999999998

---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
Input In [52], in <cell line: 5>()
      2     return 0.3-0.2
      4 print(zeroDotThreeMinusZeroDotTwo())
----> 5 assert zeroDotThreeMinusZeroDotTwo() == 0.1, "Math too simple to fail"

AssertionError: Math too simple to fail
In [53]:
assert abs(zeroDotThreeMinusZeroDotTwo() - 0.1) < 0.001, "Precision problems!"
In [55]:
print(42/7

#def hello():
#      print("World!")

  Input In [55]
    #      print("World!")
                          ^
SyntaxError: incomplete input
In [56]:
print(42/7

def hello():
      print(

  Input In [56]
    def hello():
    ^
SyntaxError: invalid syntax