值

37.0459

file.txt

37.04278,-95.58895
37.04369,-95.58592
37.04369,-95.58582
37.04376,-95.58557
37.04376,-95.58546
37.04415,-95.58429
37.0443,-95.5839
37.04446,-95.58346
37.04461,-95.58305
37.04502,-95.58204
37.04516,-95.58184
37.04572,-95.58139
37.04597,-95.58127
37.04565,-95.58073
37.04546,-95.58033
37.04516,-95.57948
37.04508,-95.57914
37.04494,-95.57842
37.04483,-95.5771
37.0448,-95.57674
37.04474,-95.57606
37.04467,-95.57534
37.04462,-95.57474
37.04458,-95.57396
37.04454,-95.57274
37.04452,-95.57233
37.04453,-95.5722
37.0445,-95.57164
37.04448,-95.57122
37.04444,-95.57054
37.04432,-95.56845
37.04432,-95.56834
37.04424,-95.5668
37.044,-95.56251
37.04396,-95.5618

预期结果

37.04502,-95.58204
37.04516,-95.58184
37.04572,-95.58139
37.04597,-95.58127
37.04565,-95.58073
37.04546,-95.58033
37.04516,-95.57948

其他信息

在Linux中，我可以使用grep，sed，cut和其他命令获得最接近的行并进行所需的处理，但是我想在Python中使用。

任何帮助将不胜感激！谢谢。

Answer 1

如何搜索第一个“纬度，经度”的值在Python中的“ file.txt”列表中进行协调，并获得3行以上和3 下面的行？*

您可以尝试：

with open("text_filter.txt") as f:
    text = f.readlines() # read text lines to list

    filter= "37.0459"
    match = [i for i,x in enumerate(text) if filter in x] # get list index of item matching filter
    if match:
        if len(text) >= match[0]+3: # if list has 3 items after filter, print it
            print("".join(text[match[0]:match[0]+3]).strip())
        print(text[match[0]].strip())
        if match[0] >= 3:  # if list has 3 items before filter, print it
            print("".join(text[match[0]-3:match[0]]).strip())

输出：

37.04597,-95.58127
37.04565,-95.58073
37.04546,-95.58033
37.04597,-95.58127
37.04502,-95.58204
37.04516,-95.58184
37.04572,-95.58139

Answer 2

您可以使用熊猫将数据导入到数据框中，然后轻松进行操作。根据您的问题，要检查的值不完全匹配，因此我将其转换为字符串。

WITH

输出

import pandas as pd
data = pd.read_csv("file.txt", header=None, names=["latitude","longitude"]) #imports text file as dataframe
value_to_check = 37.0459 # user defined
for i in range(len(data)):
    if str(value_to_check) == str(data.iloc[i,0])[:len(str(value_to_check))]:
        break
print(data.iloc[i-3:i+4,:])

Answer 3

带有迭代器的解决方案，该解决方案仅在内存中保留必要的行，而不会加载文件的不必要部分：

from collections import deque
from itertools import islice


def find_in_file(file, target, before=3, after=3):

    queue = deque(maxlen=before)
    with open(file) as f:
        for line in f:
            if target in map(float, line.split(',')):
                out = list(queue) + [line] + list(islice(f, 3))
                return out
            queue.append(line)
        else:
            raise ValueError('target not found')

一些测试：

print(find_in_file('test.txt', 37.04597))

# ['37.04502,-95.58204\n', '37.04516,-95.58184\n', '37.04572,-95.58139\n', '37.04597,-95.58127\n',
#  '37.04565,-95.58073\n', '37.04565,-95.58073\n', '37.04565,-95.58073\n']

print(find_in_file('test.txt', 37.044))  # Only one line after the match

# ['37.04432,-95.56845\n', '37.04432,-95.56834\n', '37.04424,-95.5668\n', '37.044,-95.56251\n', 
#   '37.04396,-95.5618\n']

此外，如果匹配之前或之后的行数少于预期的行数，它也可以工作。我们匹配浮点数而不是字符串，因为否则“ 37.04”会错误地匹配“ 37.0444”。

Answer 4

即使小于3，此解决方案也会打印出before和after元素。我也正在使用字符串，因为这个问题暗示您也想要部分匹配。 即。 37.0459将匹配37.04597

search_term='37.04462'
with open('file.txt') as f:
    lines = f.readlines()
lines = [line.strip().split(',') for line in lines] #remove '\n'
for lat,lon in lines:
    if search_term in lat:
        index=lines.index([lat,lon])
        break
left=0
right=0
for k in range (1,4): #bcoz last one is not included
    if index-k >=0:
        left+=1
    if index+k<=(len(lines)-1):
        right+=1
for i in range(index-left,index+right+1): #bcoz last one is not included
    print(lines[i][0],lines[i][1])

根据Python中的值查找文本的第一行

值

file.txt

预期结果

其他信息

4 个答案: