以下は、空ではなく、マークされていない 10 行をランダムに選択します。選択された行が印刷され、ファイルが更新され、選択された行がマークされ (先頭に が追加され*
)、空の行が削除されます。
import random
num_lines = 10
# read the contents of your file into a list
with open('master.txt', 'r') as f:
lines = [L for L in f if L.strip()] # store non-empty lines
# get the line numbers of lines that are not marked
candidates = [i for i, L in enumerate(lines) if not L.startswith("*")]
# if there are too few candidates, simply select all
if len(candidates) > num_lines:
selected = random.sample(candidates, num_lines)
else:
selected = candidates # choose all
# print the lines that were selected
print "".join(lines[i] for i in selected)
# Mark selected lines in original content
for i in selected:
lines[i] = "*%s" % lines[i] # prepend "*" to selected lines
# overwrite the file with modified content
with open('master.txt', 'w') as f:
f.write("".join(lines))