Question

当我打电话给show_magicians时，会打印出他们的名字，但是我想，当我打电话给make_great时，他们的名字会被添加。

def make_great(magician_names):
    """Adds the phrase 'the Great' to each magician's name."""
    for name in magician_names:
        # I want to add 'the Great' to each item in the list
        # magician_names so that when I call show_magicians, 
        # the items in the list will have 'the Great' added 
        # to them.

def show_magicians(magician_names):
    """Print the names of magicians in a list."""
    for name in magician_names:
        print(name.title())

magician_names = ['peter', 'maria', 'joshua']
show_magicians(magician_names)
make_great(magician_names)
show_magicians(magician_names)

Answer 1

请注意，magician_names中的for name不允许您更改名称的列表值，因为Python中的字符串无法就地更改，您必须用新值替换它们。您必须使用magician_names [0] ...等直接编辑列表。这里我返回了一个包含更改名称的新列表，这是处理传递给方法的列表的首选方法。

def make_great(magician_names):
    """Adds the phrase 'the Great' to each magician's name."""
    return [ name + ' the Great' for name in magician_names]


def show_magicians(magician_names):
    """Print the names of magicians in a list."""
    for name in magician_names:
        print(name.title())

magician_names = ['peter', 'maria', 'joshua']
show_magicians(magician_names)
magician_names = make_great(magician_names)
show_magicians(magician_names)

这是一种直接更改列表的方法：

def make_great(magician_names):
    """Adds the phrase 'the Great' to each magician's name."""
    for index in range(len(magician_names)):
        magician_names[index] += ' the Great'

Answer 2

#!/usr/bin/python

def make_great(magician_names):
        """Adds the phrase 'the Great' to each magician's name."""
        for name in magician_names:
                print "{} the Great".format(name)

def show_magicians(magician_names):
        """Print the names of magicians in a list."""
        for name in magician_names:
                print(name.title())

magician_names = ['peter', 'maria', 'joshua']
show_magicians(magician_names)
make_great(magician_names)
show_magicians(magician_names)

无法弄清楚如何在Python中修改函数中的列表项？

2 个答案: