Question

嘿伙计，所以我有一个文本文件，我试图从中读取并接收每个数字字符串并将其转换为浮点数。但是每当我尝试它时，它都会说“把绳子转换成浮子”。为什么会这样？谢谢！

try:
    input_file = open("Dic9812.TFITF.encoded.txt","r")
    output_fileDec = open("Dic9812.TFITF.decoded.txt","w")
    output_fileLog = open("Dic9812.TFITF.log.txt","w")
except IOError:
    print("File not found!")

coefficientInt = input("Enter a coefficient: ")
coefficientFl = float(coefficientInt)
constInt = input("Enter a constant: ")
constFl = float(constInt)

try:
    for line in input_file:
        for numstr in line.split(","):
            numFl = float(numstr)
            print(numFl)
except Exception as e:
    print(e)

该文件如下所示：

135.0,201.0,301.0
152.0,253.0,36.0,52.0
53.0,25.0,369.0,25.0

它最终会打印数字，但最后却说：无法将字符串转换为float：

Answer 1

在第二行的末尾，您有一个逗号，因此列表中有一个空字符串。 float('')引发异常，因此您的错误：

for line in input_file:
    for numstr in line.split(","):
        if numstr:
            try:
                numFl = float(numstr)
                print(numFl)
            except ValueError as e:
                print(e)

如评论中所述，请避免捕获Exception并尝试在try/except中使用最少的代码行以避免无提示错误。

Answer 2

输入f

135.0,201.0,301.0
152.0,253.0,36.0,52.0
53.0,25.0,369.0,25.0

Python f.py

import sys

for line in sys.stdin.readlines():
    fs = [float(f) for f in line.split(",")]
    print fs

<强>用法

$ python f.py < f

<强>输出

[135.0, 201.0, 301.0]
[152.0, 253.0, 36.0, 52.0]
[53.0, 25.0, 369.0, 25.0]

如何在从文本文件中读取时将字符串转换为浮点数

2 个答案: