Python中如何用循环实现按指定行数遍历列表并打印内容？

现有Python代码定义：

lyrics = ["I want to break free", "I want to break free",
          "I want to break free", "yes, I want to break free"]
number_of_lines = 6

需要创建一个循环，打印number_of_lines指定的行数。示例中需要遍历lyrics列表1.5次：

• 先打印整个列表（共4行）
• 再打印列表的前2行，从而达到6行的要求

目前写出的代码只能打印整个列表：

for line in lyrics:
   print(line)

请问具体该如何实现这一需求？

方法一：手动计算完整循环与剩余行数 #

通过整除和模运算拆分完整遍历次数与剩余需要打印的行数，分两部分处理：

lyrics = ["I want to break free", "I want to break free",
          "I want to break free", "yes, I want to break free"]
number_of_lines = 6

lyrics_len = len(lyrics)
# 计算需要完整遍历列表的次数
full_rounds = number_of_lines // lyrics_len
# 计算遍历完完整轮次后剩余需要打印的行数
remaining = number_of_lines % lyrics_len

# 打印完整轮次的内容
for _ in range(full_rounds):
    for line in lyrics:
        print(line)

# 打印剩余的行数
for line in lyrics[:remaining]:
    print(line)

方法二：利用迭代工具简化代码 #

借助itertools.cycle生成无限循环的迭代器，再通过islice截取前number_of_lines个元素打印，代码更简洁：

from itertools import cycle, islice

lyrics = ["I want to break free", "I want to break free",
          "I want to break free", "yes, I want to break free"]
number_of_lines = 6

for line in islice(cycle(lyrics), number_of_lines):
    print(line)

也可以用循环计数的方式实现，不需要islice：

from itertools import cycle

lyrics = ["I want to break free", "I want to break free",
          "I want to break free", "yes, I want to break free"]
count = number_of_lines = 6

for line in cycle(lyrics):
    if count <= 0:
        break
    print(line)
    count -= 1

内容的提问来源于stack exchange，提问作者Mike