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Exercise

Exercise

Answer the Questions

  • Which value does hello_world return?

def hello_world():
    print("Hello World")

  • what is the difference between hello_word and hello_world_string?

def hello_world_string():
    return "Hello World"

  • What is the type of hello_world_string and hello_world_string()?

  • Write a function with three arguments. Execute this function with different combinations of keyword and positional arguments. What is allowed, what is not? What rules can be derived from that result?

  • Write a function with two arguments. One should have a default value. At which position does it need to be placed in the signature?

  • Describe the behaviour of the following program. Change the code such that the function always returns the same data.

def append_element(e, l=[1]):
    l.append(e)
    return l

print(append_element(2))
print(append_element(2, [5]))
print(append_element(2))
print(append_element(2))

  • Of what type are the parameter args and kwargs in the following function?

def func_pos_args(*args, **kwargs):
    print(args, kwargs)

  • Read PEP257 and write a proper docstring for the function append_element from above.

  • Swap the order of instructions in the body of the function below. What happens?

s3 = "I hate {}"
def f(city):
    s3 = "I love {}"
    print(s3.format(city))
    
f('Paris')
print(s3.format('Paris'))

Coding exercise

Write the following functions with reasonable default values and a docstring:

  • A function which checks, if a coordinate tuple lies within a circle with centre M and radius r (in 2D).

  • A function which returns the refractive index of water and ice for wavelengths between 0.2 μm and 1.2 μm. Conditions as they are typically on earths surface (e.g. right now) should be used as default.

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