使用Python操纵键值分组的txt文件表示形式 [英] Use Python to manipulate txt file presentation of key-value grouping

问题描述

我试图使用Python来处理格式A中的文本文件:

I am trying to use Python in order to manipulate a text file from Format A:

Key1  
Key1value1  
Key1value2  
Key1value3  
Key2  
Key2value1  
Key2value2  
Key2value3  
Key3... 

转换为格式B:

Key1 Key1value1  
Key1 Key1value2  
Key1 Key1value3  
Key2 Key2value1  
Key2 Key2value2  
Key2 Key2value3  
Key3 Key3value1...

具体来说，这是文件本身的简要介绍(仅显示一个键，整个文件中还有数千个键):

Specifically, here is a brief look at the file itself (only one key shown, thousands more in the full file):

chr22:16287243: PASS  
patientID1  G/G  
patientID2  G/G  
patient ID3 G/G

和所需的输出在这里:

chr22:16287243: PASS  patientID1    G/G  
chr22:16287243: PASS  patientID2    G/G  
chr22:16287243: PASS  patientID3    G/G

我已经编写了以下代码，可以检测/显示键，但是我在编写代码以存储与每个键关联的值时遇到麻烦，随后无法打印这些键值对.谁能帮我完成这个任务?

I've written the following code which can detect/display the keys, but I am having trouble writing the code to store the values associated with each key, and subsequently printing these key-value pairs. Can anyone please assist me with this task?

import sys
import re

records=[]

with open('filepath', 'r') as infile:
    for line in infile:
        variant = re.search("\Achr\d",line, re.I) # all variants start with "chr"
        if variant:
            records.append(line.replace("\n",""))
            #parse lines until a new variant is encountered

for r in records:
    print (r)

推荐答案

一次完成，无需存储行:

Do it in one pass, without storing the lines:

with open("input") as infile, open("ouptut", "w") as outfile:
    for line in infile:
        if line.startswith("chr"):
            key = line.strip()
        else:
            print >> outfile, key, line.rstrip("\n")

此代码假定第一行包含一个键，否则将失败.

This code assumes the first line contains a key and will fail otherwise.

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