python之将文件输出存储在字典中

我有一个包含两列的文件，如下所示

-34G     trendmar 
+41G     trendmar 
 1.4G    ttpsenet 
 3.6G    tyibahco 
-13M     uberhelp 
+19M     uberhelp 
-8.9G    umljgate 
+9.2G    umljgate 

我想将它存储在字典中以进行一些数学运算，但使用第一列作为值，第二列作为键。

我该怎么做？

请您参考如下方法:

您可以逐行读取您的文件，在空格处拆分并反向使用元素来创建字典:

with open("your_file", "r") as f:  # open the file for reading 
    # read it line by line, split and invert the fields to use as k:v for your dict 
    data = dict(reversed(line.split()) for line in f) 
    # {'trendmar': '+41G', 'ttpsenet': '1.4G', 'tyibahco': '3.6G', 
    #  'uberhelp': '+19M', 'umljgate': '+9.2G'} 

请注意 dict 本质上是一个 HashMap ，因此它不能有重复的键 - 如果重复键的值出现在文件中，它们将被最新的值覆盖。

更新:如果您想保留所有值，您必须将它们存储为列表，例如:

import collections 
 
data = collections.defaultdict(list)  # initiate all fields as lists 
with open("your_file", "r") as f:  # open the file for reading 
    for line in f:  # read the file line by line 
        value, key = line.split()  # split the line to value and key 
        data[key].append(value)  # append the value to the list for its key 

现在您的数据将如下所示:

{'trendmar': ['-34G', '+41G'], 'ttpsenet': ['1.4G'], 'tyibahco': ['3.6G'], 
 'uberhelp': ['-13M', '+19M'], 'umljgate': ['-8.9G', '+9.2G']} 

更新 2: 如果您想对值求和，您首先需要将它们转换为 float ，然后使用常规算术运算得出最终值，因此首先编写一个函数来转换从 SI 速记符号到原生 float:

QUANTIFIER_MAP = {"p": 1e15, "t": 1e12, "g": 1e9, "m": 1e6, "k": 1e3} 
def si_to_float(number): 
    try: 
        last_char = number[-1].lower() 
        if last_char in QUANTIFIER_MAP: 
            return float(number[:-1]) * QUANTIFIER_MAP[last_char] 
        return float(number) 
    except ValueError: 
        return 0.0 

现在您可以在创建 data 时将 list 替换为 float 并对值求和而不是追加:

import collections 
 
data = collections.defaultdict(float)  # initiate all fields as integers 
with open("your_file", "r") as f:  # open the file for reading 
    # read it line by line, split and invert the fields to use as k:v for your dict 
    for line in f:  # read the file line by line 
        value, key = line.split()  # split the line to value and key 
        data[key] += si_to_float(value)  # convert to float and add to the value for this key 

这将导致 data 为:

{'trendmar': 7000000000.0, 'ttpsenet': 1400000000.0, 'tyibahco': 3600000000.0, 
 'uberhelp': 6000000.0, 'umljgate': 300000000.0} 

如果您想将这些值返回为 SI 缩写符号，则必须编写 si_to_float() 的相反函数，然后转换您所有的data 使用它的值，即:

QUANTIFIER_STACK = ((1e15, "p"), (1e12, "t"), (1e9, "g"), (1e6, "m"), (1e3, "k")) 
def float_to_si(number): 
    for q in QUANTIFIER_STACK: 
        if number >= q[0]: 
            return "{:.1f}".format(number / q[0]).rstrip("0").rstrip(".") + q[1].upper() 
    return "{:.1f}".format(number).rstrip("0").rstrip(".") 
 
# now lets traverse the previously created 'data' and convert its values: 
for k, v in data.items(): 
    data[k] = float_to_si(v) 

最后，这将导致 data 包含:

{'trendmar': '7G', 'ttpsenet': '1.4G', 'tyibahco': '3.6G', 
 'uberhelp': '6M', 'umljgate': '300M'}