在 Python 中打印列表列表

作者

目录

Print a list of lists on separate lines in Python

  1. 在 Python 中的不同行上打印列表列表
  2. 通过在 Python 中格式化每一行来打印列表列表
  3. 在 Python 中以表格格式打印列表列表
  4. 通过使用分隔符连接每个子列表的元素来打印列表列表

在 Python 中的不同行上打印列表列表

要在单独的行上打印列表列表：

  1. 使用for循环遍历列表。
  2. 使用可迭代的解包操作符来解包每个子列表的项目。
  3. 使用print()函数打印结果。
主程序
list_of_lists = [
    [1, 'alice'],
    [2, 'bobbyhadz'],
    [3, 'carl'],
]

for sublist in list_of_lists:
    # 1 alice
    # 2 bobbyhadz
    # 3 carl
    print(*sublist)

*可迭代解包运算符
使我们能够在函数调用、推导式和生成器表达式中解包可迭代对象。

如果您只需要打印每个子列表的特定项目，请在索引处访问它们。

主程序
list_of_lists = [
    [1, 'alice'],
    [2, 'bobbyhadz'],
    [3, 'carl'],
]

for sublist in list_of_lists:
    # alice
    # bobbyhadz
    # carl
    print(sublist[1])

通过在 Python 中格式化每一行来打印列表列表

如果需要以特定方式格式化每一行，则可以使用格式化字符串文字。

主程序
list_of_lists = [
    [1, 'alice'],
    [2, 'bobbyhadz'],
    [3, 'carl'],
]

for sublist in list_of_lists:
    # id: 1 | name: alice
    # id: 2 | name: bobbyhadz
    # id: 3 | name: carl
    print(f'id: {sublist[0]} | name: {sublist[1]}')
格式化字符串文字 (f-strings) 让我们通过在字符串前加上f.
主程序
var1 = 'bobby'
var2 = 'hadz'

result = f'{var1}{var2}'
print(result)  # 👉️ bobbyhadz

确保将表达式括在大括号 –{expression}中。

在 Python 中以表格格式打印列表列表

如果您需要以
表格格式打印列表列表，您可以使用相同的方法。

主程序
headers = [
    'ID',
    'Name',
    'Country'
]

list_of_lists = [
    [1, 'alice', 'Austria'],
    [2, 'bobbyhadz', 'Bulgaria'],
    [3, 'carl', 'Canada'],
]

print(f'{headers[0]: <10}{headers[1]: <15}{headers[2]}')
# ID        Name           Country
# 1         alice          Austria
# 2         bobbyhadz      Bulgaria
# 3         carl           Canada
for row in list_of_lists:
    print(f'{row[0]: <10}{row[1]: <15}{row[2]}')

Formatted string literals also enable us to use the
format-specific mini-language
in expression blocks.

main.py
my_str = 'hi'

# 👇️ left-aligned
result = f'{my_str: <6}'
print(repr(result))  # 👉️ 'hi    '


# 👇️ right-aligned
result = f'{my_str: >6}'
print(repr(result))  # 👉️ '    hi'

The space between the colon and the less-than sign is the fill character.

The less-than or greater-than sign is the alignment.

The less-than sign aligns the string to the left and the greater-than sign aligns the string to the right.

We first format and print the headers and then iterate over the list and print
each row.

Print a List of Lists by joining the elements of each sublist with a delimiter #

You can use the str.join() method if you need to join the elements of each
sublist with a delimiter.

main.py
list_of_lists = [
    [1, 'alice'],
    [2, 'bobbyhadz'],
    [3, 'carl'],
]

# 1, alice
# 2, bobbyhadz
# 3, carl
for sublist in list_of_lists:

    result = ', '.join(str(item) for item in sublist)
    print(result)

The str.join method
takes an iterable as an argument and returns a string which is the concatenation
of the strings in the iterable.

Note that the method raises a TypeError if there are any non-string values in the iterable.

If your iterable contains numbers or other types, convert all of the values to
strings before calling join().

The string the method is called on is used as the separator between the
elements.

We used a comma and a space (, ) in the example, but you can use any other
delimiter.

If you need to join the list of lists into a string that contains newline (\n)
characters, use two calls to the str.join() method.

main.py
list_of_lists = [
    [1, 'alice'],
    [2, 'bobbyhadz'],
    [3, 'carl'],
]

result = '\n'.join(' '.join(str(item) for item in sublist)
                   for sublist in list_of_lists)
# 1 alice
# 2 bobbyhadz
# 3 carl
print(result)
The inner call to the join() method joins the elements of the sublist of the current iteration.

We used a space separator when joining the elements of each sublist, but you can
use any other delimiter.

在调用之前，我们使用str()该类将每个值转换为字符串
join()。

最后一步是使用该join()方法将列表中的子列表连接成一个字符串，以换行符 ( \n) 字符分隔符。

由于换行符，每个嵌套列表的项目都打印在单独的行上。

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