将列表添加到新列表

Question

我没答对这个问题。函数 read_words 将一个在新行中包含一堆名称的文本文件转换为一个列表，并且可以正常工作。

def read_words(words_file):
    """ (file open for reading) -> list of str
    Return a list of all words (with newlines removed) from open file
    words_file.
    Precondition: Each line of the file contains a word in uppercase characters
    from the standard English alphabet.
    """
    words_list = []
    words = words_file.readlines()
    for i in range(len(words)):
        new_word = words[i]
        for char in '\n':
            new_word = new_word.replace(char,'')
            words_list.append(new_word)
    return words_list

当我尝试获取列表列表时出现问题

def read_board(board_file):
    """ (file open for reading) -> list of list of str
    Return a board read from open file board_file. The board file will contain
    one row of the board per line. Newlines are not included in the board.
    """
    board_list = []
    row_list = []
    rows = read_words(board_file)
    for i in range(len(rows)):
        for  char in rows[i]:
            row_list.append(char)
        board_list.append(row_list)
    return board_list

目标是转换以下类型的文本文件：

ABCD
EFGH

进入[['A','B','C','D'],['E','F','G','H']]

我已经尝试过使用 board_list.append(row_list) 调用的索引，但没有成功。我怎样才能让它工作？

Answer 1

你可以用 list comprehension and .strip() 这样的方式来做到这一点：

代码：

def read_board(board_file):
    return [list(line.strip()) for line in read_words(board_file)]

测试代码：

def read_words(words_file):
    """ (file open for reading) -> list of str
    Return a list of all words (with newlines removed) from open file
    words_file.
    Precondition: Each line of the file contains a word in uppercase characters
    from the standard English alphabet.
    """
    return [word.strip() for word in words_file.readlines()]

def read_board(board_file):
    """ (file open for reading) -> list of list of str
    Return a board read from open file board_file. The board file will contain
    one row of the board per line. Newlines are not included in the board.
    """
    return [list(line) for line in read_words(board_file)]

with open('file1', 'rU') as f:
    board = read_board(f)

print(board)

结果：

[['A', 'B', 'C', 'D'], ['E', 'F', 'G', 'H']]

将列表添加到新列表

Adding lists to a new list

python

nested-lists

代码：

测试代码：

结果：