如何将序数添加到文本文件中每一行的开头
Posted
技术标签:
【中文标题】如何将序数添加到文本文件中每一行的开头【英文标题】：How to add ordinal numbers to the start of each line in text file 【发布时间】：2019-09-11 01:26:14 【问题描述】：我有一个存储在文件中的游戏排行榜。文件的格式是这样的：
bob has 46 points
fred has 0 points
leo has 27 points
我有这个代码来按从升到降的顺序显示分数：
if ens == "s":
print("\n"+"LeaderBoard: "+"\n")
f = open("scores.txt","r")
lines = list(f) #create a list of strings
f.close() #don't forget to close our files when we're done. It's good practice.
modified_lines = [] #empty list to put our modified lines in (extracted number, original line)
for line in lines: #iterate over each line
if line.strip(): #if there's anything there after we strip away whitespace
score = line.split(' ')[2] #split our text on every space and take the third item
score = int(score) #convert the string of our score into a number
modified_lines.append([score, line]) #add our modified line to modified_lines
#sort our list that now has the thing we want to sort based on is first
sorted_modified_lines = sorted(modified_lines, reverse = True )
#take only the string (not the number we added before) and print it without the trailing newline.
for line in sorted_modified_lines: print(line[1].strip()+"\n")
输出：
bob has 46 points
leo has 27 points
fred has 0 points
我想要的是分数在分数前面显示序号，如下所示：
1st. bob has 46 points
2nd. leo has 27 points
3rd. fred has 0 points
我看过其他帖子显示如何显示序数，但我仍然不知道如何做到这一点。
【问题讨论】：
【参考方案1】：这样的……
def ordinal_string(i):
if i >= 10 and i <= 20:
suffix = 'th'
else:
il = i % 10
if il == 1:
suffix = 'st'
elif il == 2:
suffix = 'nd'
elif il == 3:
suffix = 'rd'
else:
suffix = 'th'
return str(i) + suffix + '. '
然后：
for i, line in enumerate(sorted_modified_lines): print(ordinal_string(i+1) + line[1].strip()+"\n")
【讨论】：
【参考方案2】：将最后一行替换为下面两行，序数取自here
suf = lambda n: "%d%s"%(n,1:"st",2:"nd",3:"rd".get(n if n<20 else n%10,"th"))
for index, line in enumerate(sorted_modified_lines): print(suf(index + 1) + '. ' + line[1].strip()+"\n")
【讨论】：
以上是关于如何将序数添加到文本文件中每一行的开头的主要内容，如果未能解决你的问题，请参考以下文章