如何打印由数字列表指定的文件行？

Question

我打开一本字典，拉特定的行行行将指定使用一个列表，在最后我需要打印一个完整的句子在一行。你知道吗

我想打开一本每行都有一个单词的词典 然后在一行中打印一个句子，单词之间留有空格：

N = ['19','85','45','14']
file = open("DICTIONARY", "r") 
my_sentence = #?????????

print my_sentence

Answer 1

这里有一个简单的方法，有更基本的方法：

n = ['2','4','7','11']
file = open("DICTIONARY")
counter = 1                    # 1 if you're gonna count lines in DICTIONARY
                               # from 1, else 0 is used
output = ""
for line in file:
    line = line.rstrip()       # rstrip() method to delete \n character,
                               # if not used, print ends with every
                               # word from a new line   
    if str(counter) in n:
        output += line + " "
    counter += 1
print output[:-1]              # slicing is used for a white space deletion
                               # after last word in string (optional)