按文本文件中的整数打印排序的城市名称

如何解决按文本文件中的整数打印排序的城市名称

我有一个文本文件，每行都有一个城市和一个数字，如下所示：

city1 15
city2 25
city3 2
city4 8
city5 10

我想按照从最低数字到最高数字的顺序打印城市

打印应该是这样的：

city3,city4,city5,city1,city2  

试过这个：

lst = []
with open('livrari.txt',mode='r') as my_file:
    for line in my_file:
       lst.append(line.strip())
lst.sort()

print(lst)

这给了我一个包含城市和号码的列表。有人能帮我完成这个吗？

解决方法

cities = """city1 15
city2 25
city3 2
city4 8
city5 10"""

d = {}
for city_row in cities.splitlines():
    city,num = city_row.split(' ')
    d[int(num)] = city

d = dict(sorted(d.items())) # Sort

print([d[k] for k in d])

->

['city3','city4','city5','city1','city2']

,

你快到了。您只需要告诉元组中的 list sorting to make use of a particular value 进行排序，因为一般排序会遍历元组中的每个元素来对它们进行排序。

由于我们正在查看元组的第二个元素，即数字字段，我们将使用它进行排序，如下所示：

lst = []
with open('livrari.txt',mode='r') as my_file:
    for line in my_file:
        city,number = line.strip().split(' ')
        # Note that the number field needs to be converted to an integer since
        # having them on string would not reap you the numeric sort
        number = int(number)
        lst.append((city,number))
# The key argument to the sort method is used to tell the list sort to pick a particular field for sorting in terms of nested structures like this one.
lst.sort(key=lambda x: x[1])

print(lst)
[('city3',2),('city4',8),('city5',10),('city1',15),('city2',25)]

,

以下是为了使其正常工作而对代码进行的最小更改：

Try it online!

lst = []
with open('livrari.txt',mode='r') as my_file:
    for line in my_file:
       lst.append(line.split())
lst.sort(key = lambda e: int(e[1]))
print(','.join([e[0] for e in lst]))

输出：

city3,city4,city5,city1,city2

对于输入：

city1 15
city2 25
city3 2
city4 8
city5 10

,

您可以使用 lambda 根据第二列中的数字对数据进行排序。

with open('csvfile1.csv') as input:
    reader = csv.reader(input,delimiter = " ")
    sortedlist = sorted(reader,key=lambda col: int(col[1]),reverse=False)
print(",".join([lst[0] for lst in sortedlist]))
# city3,city2