如何閱讀夾着一個特定字符之間的數據（Python的3.3）

Question

好吧，技術上我被分配一個任務來完成，它涉及循環（同時，對等），我遇到了一個問題：

有人問我存儲在一個列表格式的得分和用戶名，級別等這樣的：

# <username>, <level>, <level_score> - Like this: 
['buzzysin,5,100','apple_maple,3,60','choco_charlie,2,25','buzzysin,1,10'] 

我需要做的就是使用這些數據創建一個記分牌，但我似乎無法隔離分數來自列表中的字符串。這裏是我的代碼片段：

def scoreboard(): 
    name = input("Enter a username: ") # Say 'buzzysin' 
    t = open('scores.txt', 'r') 
    a = t.readlines() 
    b = [] 
    t.close() 
    for i in range(len(a)): 
     if name not in a[i]: 
      pass 
     else: # Here I need to get the occurences of 'buzzysin' and append it to b 
      b.append(a[i]) 
    #Then I need to extract the level and scores, but here's where I'm stuck :-(

我的記分牌需要是這樣的：

>>> scoreboard() 
Please enter a name: buzzysin 
The scores for buzzysin are: 

    Level Scores 
----------------------- 
     1  10 
     2   0 
     3   0 
     4   0 
     5  100 

>>> 

請幫幫忙，

'buzzysin'

Answer 1

轉到模塊化！編寫一個單獨的函數來解析每一行，使用它來解析所有行，然後過濾出相關人員的分數。列表理解爲這是偉大的：

def parse_line(line): 
    """parse a score line, returning its data 

    A score line is of the form: <username>,<level>,<level_score> 

    The level and score are integers. 
    """ 
    parts = line.split(',') 
    if len(parts) != 3: 
     return None # or raise an exception 
    name = parts[0] 
    level = int(parts[1]) 
    level_score = int(parts[2]) 
    return name, level, level_score 

# read the lines 
with open('scores.txt', 'r') as t: 
    lines = t.readlines() 

# parse the lines, ignoring empty lines 
scores = [parse_line(line) for line in lines if line != ""] 

# get the person's name 
name = input("Enter a username: ") # Say 'buzzysin' 

# filter that person's scores 
persons_scores = [score for score in scores if score[0] == name] 

# now print your table... 

Answer 2

首先，for i in len(a)會引發異常，因爲整數是不可迭代的。您要麼直接迭代a，要麼迭代range(len(a))之類的索引列表。其次，如果a中的行格式如下buzzysin,5,100您應該使用string.startswith intent in（節省很多時間）。然後，如果一個字符串以buzzysin開頭，則可以用string.split(',')解析該字符串以獲得分數。例如，

for line in a: 
    if line.startswith(player_name): 
     name, level, score = line.rstrip().split(',') 

Answer 3

只需使用.split(',')：

lines = ['buzzysin,5,100','apple_maple,3,60','choco_charlie,2,25','buzzysin,1,10'] 
for line in lines: 
    name, level, score = line.split(',') 
    print(name, 'is in level', level, 'with score', score) 

打印：

buzzysin is in level 5 with score 100 
apple_maple is in level 3 with score 60 
choco_charlie is in level 2 with score 25 
buzzysin is in level 1 with score 10 

Answer 4

# get all scoreboard data 
data = ['buzzysin,5,100','apple_maple,3,60','choco_charlie,2,25','buzzysin,1,10'] 
# get target name 
target_name = input("Enter a username: ") 
# initialize our target scoreboard 
target_scoreboard = {} 
# get scoreboard data for our target 
for name_data in data: # look at all the data, one item at a time 
    if name_data.split(',')[0] == target_name: 
     # if this data is for our target, add it to out target scoreboard 
     level = int(name_data.split(',')[1]) 
     score = int(name_data.split(',')[2]) 
     target_scoreboard[level] = score 

# print scoreboard for our target, sorted by level 
print("\tLevel\tScore") 
print("-"*25) 
for level in sorted(target_scoreboard): 
    print('\t{:d}\t{:d}'.format(level, target_scoreboard[level]))