Question

我有以下文本文件：

0 something 0.008
0 something2 0.004
0 something3 0.003
0 something4 0.001
0 something5 0.000
1 something 0.008
1 something2 0.004
1 something3 0.003
1 something4 0.001
1 something5 0.000

以及下面的代码读取文件，并且仅占用从0开始的前3行，从1开始的前3行，依此类推。到目前为止，除了最后添加浮点数（在代码中标记为w）之外，它都成功地完成了这一任务，由于强制转换，我很难添加它。

with open('output.txt', mode = 'r') as f:   
    MAX = 3                             
    i = 0
    weight=0
    output = []
    while True:
        line = f.readline().strip()       
        if line == '':                    
            break 
        line = line.split()  
        i = int(line[0])
        w=float(line[2]) # I want to add this at the end of every line as well


        try:
            output[i]
        except IndexError:
            for i in range(len(output), i + 1):
                output.append([])         
        if len(output[i]) < MAX:        
            output[i].append(line[1]) 


for i, j in enumerate(output):
    print(i, *j)

所需的输出：

0 something 0.008 something2 0.004 something3 0.003
1 something 0.00 something2 0.004 something3 0.003

如何添加它？提前非常感谢您！

Answer 1

读取文件的每一行，然后将每一行数据添加到collections.defaultdict()中，确保每一行的第一项是分组密钥，然后仅从每一行中提取[:3]最后分组：

from collections import defaultdict

d = defaultdict(list)
with open("test.txt") as f:
    for line in f:
        key, *rest = line.split()
        d[key].append(rest)

for k, v in d.items():
    print("%s %s" % (k, " ".join("%s %s" % (x, y) for x, y in v[:3])))

哪些输出：

0 something 0.008 something2 0.004 something3 0.003
1 something 0.008 something2 0.004 something3 0.003

Answer 2

您只需使用str（w）即可将其转换为字符串

with open('output.txt', mode = 'r') as f:   
    MAX = 3                             
    i = 0
    weight=0
    output = []
    while True:
        line = f.readline().strip()       
        if line == '':                    
            break 
        line = line.split() 
        print("line ",line) 
        i = int(line[0])
        w=float(line[2]) # I want to add this at the end of every line as well

        try:
            output[i]
        except IndexError:
            for i in range(len(output), i + 1):
                output.append([])         
        if len(output[i]) < MAX:        
            output[i].append(line[1]+" "+str(w))



for i, j in enumerate(output):
    print(i, j)

Python从文件读取浮点数并将其附加在每一行的末尾

2 个答案: