如何从文本文件中随机打印多行（使用python）

Question

I want to be able to print a number of lines from my file randomly.

This is my file:

1. What date did World War II start? 
A. 20th October 1939
B. 1st September 1939

2. Which was a youth organisation group set up by Hitler during WWII for    German youth?
A. Hitler Youth 
B. Edelweiss Pirates 

3. Who succeeded Elizabeth I on the English throne? 
A. Henry VIII
B. James VI 

4. Did Ireland take part in WWII?
A. No
B. Yes 

5.  Who was the Prime Minister of Britain at the start of WWII?
A. Neville Chamberlain 
B. Winston Churchill 

This is my current code:

#Q1
with open ("hisEasyQ.txt") as hisEasyQFile:
    for line in itertools.islice(hisEasyQFile, 0, 3):
        print line
hisEasyA1 = raw_input("Enter your choice (A or B): ").lower()
print "\n"

#Q2
with open ("hisEasyQ.txt") as hisEasyQFile:
    for line in itertools.islice(hisEasyQFile, 4, 7):
        print line
hisEasyA2 = raw_input("Enter your choice (A or B): ").lower()
print "\n"

#Q3
with open ("hisEasyQ.txt") as hisEasyQFile:
    for line in itertools.islice(hisEasyQFile, 8, 11):
        print line
hisEasyA3 = raw_input("Enter your choice (A or B): ").lower()
print "\n"

#Q4
with open ("hisEasyQ.txt") as hisEasyQFile:
    for line in itertools.islice(hisEasyQFile, 12, 15):
        print line
hisEasyA4 = raw_input("Enter your choice (A or B): ").lower()
print "\n"

#Q5
with open ("hisEasyQ.txt") as hisEasyQFile:
    for line in itertools.islice(hisEasyQFile, 16, 19):
        print line
hisEasyA5 = raw_input("Enter your choice (A or B): ").lower()
print "\n"

Currently, it prints the file in sequential order, ie:

1. What date did World War II start? 

A. 20th October 1939

B. 1st September 1939

Enter your choice (A or B): 


2. Which was a youth organisation group set up by Hitler during WWII for German  youth?

A. Hitler Youth 

B. Edelweiss Pirates 

Enter your choice (A or B): 


3. Who succeeded Elizabeth I on the English throne? 

A. Henry VIII

B. James VI 


Enter your choice (A or B): 


4. Did Ireland take part in WWII?

A. No

B. Yes 

Enter your choice (A or B): 


5.  Who was the Prime Minister of Britain at the start of WWII?

A. Neville Chamberlain 

B. Winston Churchill 

Enter your choice (A or B): 

However, I would like it to randomly print the lines each time it opens, like this:

1. Who was the Prime Minister of Britain at the start of WWII?

A. Neville Chamberlain 

B. Winston Churchill 

Enter your choice (A or B): 

2. Who succeeded Elizabeth I on the English throne? 

A. Henry VIII

B. James VI 


Enter your choice (A or B):

#...etc...

And then the next time the user runs it the questions are in a different order.

Any idea how would go about doing this using the random function?

(I am using Python 2.7)

Answer 1

You can convert the data from the text into a list and then use the random.choice method from random module to pick a random choice.

Example:

import random

path = "Path_to"
with open(path, "r") as hisEasyQFile:
    data = hisEasyQFile.read().split("\n\n")

print random.choice(data)

Answer 2

One option would be to store the questions in a list and use one of the numpy functions ( numpy.random.permutation ) for the random number generation.

For example, assuming your questions are stored as-is in the file questions.txt you could do the following:

import numpy as np

# Store the questions in a list
#
# Sample format needs to be as-is for each question i.e.:
# Question
# A....
# B....
# blank line
#
questions = []
with open("questions.txt") as fh:
    questions = fh.read().split("\n\n")

# Store the random index and the response as tuples in a list
responses = []
for i in np.random.permutation(range((len(questions)))):
    print questions[i]
    responses.append((i, raw_input("Enter your choice (A or B): ").lower()))

# Print the responses list or process it as needed
print responses