Curso de Programación en Python/CrearFunciones

Crear Funciones

a = 23
b = -23

def absolute_value( n ):
  if n < 0:
    n = -n
  return n

if absolute_value( a ) == absolute_value( b ):
  print( "El valor absoluto de", a, "y", b, "son igual." )
else:
  print( "El valor absoluto de", a, "y", b, "son diferentes." )

Lo que sigue:

El valor absoluto de 23 y -23 son igual.

def hola( ):
  print(  "Hola" )

def area( ancho, altura ):
  return ancho * altura

def print_bienvenido( nombre):
  print( "Bienvenido", nombre )

hola( )
hola( )

print_bienvenido( "Miguel")
w = 4
h = 5
print( "ancho =", w, " height =, h, " area =", area( w, h ))

Lo que sigue:

Hola
Hola
Bienveenido Miguel
ancho = 4  altura = 5  areá = 20

Variables in functions

a = 4

def print_func( ):
  a = 17
  print( "en print_func a = ", a)

print_func( )
print( "a = ", a)

Lo que sigue:

in print_func a = 17
a = 4

a_var = 10
b_var = 15
e_var = 25

def a_func( a_var ):
  print( "en a_func a_var = ", a_var )
  b_var = 100 + a_var
  d_var = 2 * a_var
  print( "en a_func b_var = ", b_var )
  print( "en a_func d_var = ", d_var )
  print( "en a_func e_var = ", e_var )
  return b_var + 10 
c_var = a_func( b_var ) 
print( "a_var = ", a_var )
print( "b_var = ", b_var )
print( "c_var = ", c_var )
print( "d_var = ", d_var )

Lo que Sigue:

in a_func a_var =  15
in a_func b_var =  115
in a_func d_var =  30
in a_func e_var =  25
a_var =  10
b_var =  15
c_var =  125
d_var = 

Traceback (most recent call last):
 File "C:\def2.py", line 19, in <module>
   print("d_var = ", d_var)
NameError: name 'd_var' is not defined

temperature2.py

1. !/usr/bin/python3
2. -*-coding: utf-8 -*-
3. convertir temperatura en Fahrenheit a Celsius

def print_options( ):

 print( "Options:" )
 print( " 'p' print options" )
 print( " 'c' convert from Celsius" )
 print( " 'f' convert from Fahrenheit" )
 print( " 'q' quit the program" )

def celsius_to_fahrenheit( c_temp ):

 return 9.0 / 5.0 * c_temp + 32

def fahrenheit_to_celsius( f_temp ):

 return ( f_temp - 32.0 ) * 5.0 / 9.0

choice = "p" while choice != "q":

 if choice == "c":
   c_temp = float( input( "Celsius temperature: " ) )
   print( "Fahrenheit:", celsius_to_fahrenheit( c_temp ) )
   choice = input( "option: " )
 elif choice == "f":
   f_temp = float( input( "Fahrenheit temperature: " ) )
   print( "Celsius:", fahrenheit_to_celsius( f_temp ) )
   choice = input( "option: " )
 elif choice == "p": #Alternatively choice != "q": so that print when anything unexpected inputed
    print_options( )
    choice = input( "option: " )

Lo que sigue:

Options:

'p' print options
'c' convert from celsius
'f' convert from fahrenheit
'q' quit the program

option: c Celsius temperature: 30 Fahrenheit: 86.0 option: f Fahrenheit temperature: 60 Celsius: 15.5555555556 option: q

area2.py

<span class="co1">#! /usr/bin/python</span>
<span class="co1">#-*-coding: utf-8 -*-</span>
<span class="co1"># calculates a given rectangle area</span>
 
<span class="kw1">def</span> hello<span class="br0">(</span><span class="br0">)</span>:
    <span class="kw1">print</span><span class="br0">(</span><span class="st0">'Hello!'</span><span class="br0">)</span>
 
<span class="kw1">def</span> area<span class="br0">(</span>width<span class="sy0">,</span> height<span class="br0">)</span>:
    <span class="kw1">return</span> width * height
 
<span class="kw1">def</span> print_welcome<span class="br0">(</span>name<span class="br0">)</span>:
    <span class="kw1">print</span><span class="br0">(</span><span class="st0">'Welcome,'</span><span class="sy0">,</span> name<span class="br0">)</span>
 
<span class="kw1">def</span> positive_input<span class="br0">(</span>prompt<span class="br0">)</span>:
    number <span class="sy0">=</span> <span class="kw2">float</span><span class="br0">(</span><span class="kw2">input</span><span class="br0">(</span>prompt<span class="br0">)</span><span class="br0">)</span>
    <span class="kw1">while</span> number <span class="sy0"><=</span> <span class="nu0">0</span>:
        <span class="kw1">print</span><span class="br0">(</span><span class="st0">'Must be a positive number'</span><span class="br0">)</span>
        number <span class="sy0">=</span> <span class="kw2">float</span><span class="br0">(</span><span class="kw2">input</span><span class="br0">(</span>prompt<span class="br0">)</span><span class="br0">)</span>
    <span class="kw1">return</span> number
 
name <span class="sy0">=</span> <span class="kw2">input</span><span class="br0">(</span><span class="st0">'Your Name: '</span><span class="br0">)</span>
hello<span class="br0">(</span><span class="br0">)</span>
print_welcome<span class="br0">(</span>name<span class="br0">)</span>
<span class="kw1">print</span><span class="br0">(</span><span class="br0">)</span>
<span class="kw1">print</span><span class="br0">(</span><span class="st0">'To find the area of a rectangle,'</span><span class="br0">)</span>
<span class="kw1">print</span><span class="br0">(</span><span class="st0">'enter the width and height below.'</span><span class="br0">)</span>
<span class="kw1">print</span><span class="br0">(</span><span class="br0">)</span>
w <span class="sy0">=</span> positive_input<span class="br0">(</span><span class="st0">'Width: '</span><span class="br0">)</span>
h <span class="sy0">=</span> positive_input<span class="br0">(</span><span class="st0">'Height: '</span><span class="br0">)</span>
 
<span class="kw1">print</span><span class="br0">(</span><span class="st0">'Width ='</span><span class="sy0">,</span> w<span class="sy0">,</span> <span class="st0">' Height ='</span><span class="sy0">,</span> h<span class="sy0">,</span> <span class="st0">' so Area ='</span><span class="sy0">,</span> area<span class="br0">(</span>w<span class="sy0">,</span> h<span class="br0">)</span><span class="br0">)</span>

Sample Run:

Your Name: <b>Josh</b>
Hello!
Welcome, Josh

To find the area of a rectangle,
enter the width and height below.

Width: <b>-4</b>
Must be a positive number
Width: <b>4</b>
Height: <b>3</b>
Width = 4  Height = 3  so Area = 12