只读文本文件中指定行中的数字

Question

我试图从文本文件的第18行和第19行读取两个浮点数并找到它们的平均值。请只查看由#########分隔的代码部分。

该文件有单词和数字的混合，我不知道如何只读取数字。第18行和第19行的示例如下：

TM-score= 0.27878 (if normalized by length of Chain_1)
TM-score= 0.36068 (if normalized by length of Chain_2)

def tmval(self,name,tmvalpath):
    dir = tmvalpath
    splits = []
    avg = 0
    number1 = 0
    number2 = 0
    for f in os.listdir(dir):
        file_name2, file_ext = os.path.splitext(f)
        n1,n2,align = file_name2.split('_')
        n = ('{}_{}'.format(n1,n2))
        if n == name:
#####################################################
            with open(os.path.join(dir,f)) as file:
                for i, line in enumerate(file):
                    if i == 17:
                       #retrieve data from 18th line
                       number1 =
                    elif i == 18:
                       # retrieve data from 19th line
                       number2 = 
######################################################
  avg = float(number1 + number2)/2                      
  return avg

Answer 1

您可以使用正则表达式：

import re

with open(os.path.join(dir,f)) as file:
    for i, line in enumerate(file):
        if i == 17:
            number1 = float(re.search(r'\d+\.\d+', line).group())

        elif i == 18:
            number2 = float(re.search(r'\d+\.\d+', line).group())

Answer 2

看起来像正则表达式的工作。

像[0-9] [。] [0-9] *之类的东西应该这样做。

蟒蛇：

import re
import numpy as np

line = 'TM-score= 0.36068 (if normalized by length of Chain_2)'

str = re.search(r'[0-9][.][0-9]*', line)
number1 = float(str.group(0))
print(number1)