编辑列表中的元素 - python

Question

我编写了一个程序，它从 excel 电子表格中获取行并将它们 returns 作为列表。我不会尝试编辑创建的每个列表：

...来自

['-1', '3', '4', '5', '3', '7', '2', '4', '0', '8', '12', '23', '4', '0']

到...

['-1', '1:3', '2:4', '3:5', '4:3', '5:7', '6:2', '7:4', '8:0', '9:8', '10:12', '11:23', '12:4', '13:0']

import csv

with open('testingSeta.csv') as csvfile:
    reader = csv.reader(csvfile)

    line = True

    for row in reader:
        if line:
            line = False
            continue

        x = row.pop()
        row.insert(0,x)        

        print(row)

Answer 1

尝试列表理解：

src =  ['-1', '3', '4', '5', '3', '7', '2', '4', '0', '8', '12', '23', '4', '0']


src[0:1] + [ str(i+1) + ":" + v for i,v in enumerate(src[1:])]

这导致：

['-1',
'1:3',
'2:4',
'3:5',
'4:3',
'5:7',
'6:2',
'7:4',
'8:0',
'9:8',
'10:12',
'11:23',
'12:4',
'13:0']

您还可以使用函数式方法：

map(lambda (i,v): v if i == 0 else str(i)+":"+v, enumerate(src))

我确实更喜欢函数式方式，但据我所知，列表理解似乎更 "pythonic"。

Answer 2

>>> a = ['-1', '3', '4', '5', '3', '7', '2', '4', '0', '8', '12', '23', '4', '0']
>>> a[:1] + ["{}:{}".format(x,y) for x,y in enumerate(a[1:], start=1)]
['-1', '1:3', '2:4', '3:5', '4:3', '5:7', '6:2', '7:4', '8:0', '9:8', '10:12', '11:23', '12:4', '13:0']

Enumerate 以元组形式访问索引和元素

使用itertools.starmap

>>> import itertools
>>> a[:1] + list(itertools.starmap("{}:{}".format, enumerate(a[1:], start=1)))
['-1', '1:3', '2:4', '3:5', '4:3', '5:7', '6:2', '7:4', '8:0', '9:8', '10:12', '11:23', '12:4', '13:0']

使用 map 和 lambda:

>>> a[:1] + map(lambda x:"{}:{}".format(x[0],x[1]), enumerate(a[1:], start=1))
['-1', '1:3', '2:4', '3:5', '4:3', '5:7', '6:2', '7:4', '8:0', '9:8', '10:12', '11:23', '12:4', '13:0']

如果要存储：

>>> a = a[:1] + ["{}:{}".format(x,y) for x,y in enumerate(a[1:], start=1)]
>>> print(a)
['-1', '1:3', '2:4', '3:5', '4:3', '5:7', '6:2', '7:4', '8:0', '9:8', '10:12', '11:23', '12:4', '13:0']

Answer 3

from_list = ['-1', '3', '4', '5', '3', '7', '2', '4', '0', '8', '12', '23', '4', '0']

for i in range(1, len(from_list)):

    new_ele = str(i)+':'+from_list[i]
    from_list[i] = new_ele
print from_list

输出将是：

['-1', '1:3', '2:4', '3:5', '4:3', '5:7', '6:2', '7:4', '8:0', '9:8', '10:12', '11:23', '12:4', '13:0']

编辑列表中的元素 - python

Edit an element in a list - python

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