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#2
Sornets2014-02-07 12:41
 程序代码：# Using functions in a dictionary instead of long if statements: # Let's say we have a variable called 'current_action' and we want stuff to happen based on its value: if current_action == 'PAUSE': pause() elif current_action == 'RESTART': restart() elif current_action == 'RESUME': resume() # This can get long and complicated if there are many values. # Instead, we can use a dictionary: response_dict = { 'PAUSE': pause, 'RESTART': restart, 'RESUME': resume } response_dict[current_action]() # Gets the correct function from response_dict and calls it//好屌，字符加个括号就成了同名函数了啊！ |
程序代码：# Returning functions from functions
# A simple function
def say_hello(greeter, greeted):
return "Hello, " + greeted + ", I'm " + greeter + "."
# We can use it like this:
print say_hello("Alice", "Bob") # Displays "Hello, Bob, I'm Alice."
# We can also use it in a function:
def produce_greeting_from_alice(greeted):
return say_hello("Alice", greeted)
print produce_greeting_from_alice("Bob") # Displays "Hello, Bob, I'm Alice."
# We can also return a function from a function by nesting them:
def produce_greeting_from(greeter):
def greet(greeted):
return say_hello(greeter, greeted)
return greet
# Here we create a greeting function for Eve:
produce_greeting_from_eve = produce_greeting_from("Eve")//这里能理解为C中#define produce_greeting_from_eve produce_greeting_from("Eve") 么？
# 'produce_greeting_from_eve' is now a function:
print produce_greeting_from_eve("Alice") # Displays "Hello, Alice, I'm Eve."
# You can also invoke the function directly if you want:
print produce_greeting_from("Bob")("Eve") # Displays "Hello, Eve, I'm Bob."
# A simple function
def say_hello(greeter, greeted):
return "Hello, " + greeted + ", I'm " + greeter + "."
# We can use it like this:
print say_hello("Alice", "Bob") # Displays "Hello, Bob, I'm Alice."
# We can also use it in a function:
def produce_greeting_from_alice(greeted):
return say_hello("Alice", greeted)
print produce_greeting_from_alice("Bob") # Displays "Hello, Bob, I'm Alice."
# We can also return a function from a function by nesting them:
def produce_greeting_from(greeter):
def greet(greeted):
return say_hello(greeter, greeted)
return greet
# Here we create a greeting function for Eve:
produce_greeting_from_eve = produce_greeting_from("Eve")//这里能理解为C中#define produce_greeting_from_eve produce_greeting_from("Eve") 么？
# 'produce_greeting_from_eve' is now a function:
print produce_greeting_from_eve("Alice") # Displays "Hello, Alice, I'm Eve."
# You can also invoke the function directly if you want:
print produce_greeting_from("Bob")("Eve") # Displays "Hello, Eve, I'm Bob."
