在python 3.x中提取文本文件的特定部分

Question

How do I make the if statement to read from a specific location of a text file and stop at a specific point and then print it out. for example, printing out one patient's data, not all the list. beginner programmer here. thank you

 ID = input("please enter a refernce id to search for the patient : ")
 info = open("data.txt", 'r')
 if ID in info: 
 # This should return only one patient's information not all the text file   
 else:
    print("not in file")
info.close()

Answer 1

We would need to know the specific details of how the file is formatted to give an exact answer, but here is one way that may be helpful.

Firstly, your 'info' is right now just a TextIOWrapper object. You can tell by running print(type(info)) . You need to make it info = open('data.txt', 'r').read() to give you a string of the text, or info = open('data.txt', 'r').readlines() to give you a list of the text by line, if the format is just plain text.

Assuming the data looks something like this:

Patient: Charlie
Age = 99
Description: blah blah blah
Patient: Judith
Age: 100
Description: blah blah blahs

You can do the following:

First, find and store the index of the ID you are looking for. Secondly, find and store the index of some string that denotes a new ID. In this case, that's the word 'Patient'. Lastly, return the string between those two indices.

Example:

ID = input("please enter a reference id to search for the patient: ")
info = open("data.txt", 'r').read()
if ID in info:
    #find() returns the beginning index of a string
    f = info.find(ID)
    goods = info[f:]
    l = goods.find('Patient')
    goods = goods[:l]
    print(goods)   
else:
    print("not in file")

Something along those lines should do the trick. There are probably better ways depending on the structure of the file. Things can go wrong if the user input is not specific enough, or the word patient is scattered in the descriptions, but the idea remains the same. You should do some error handling for the input, as well. I hope that helps! Good luck with your project.