Python 计算到文件列之间的百分比变化

Question

我知道这对某些人来说很容易，但就我而言，我需要帮助。我需要比较两个文本文件内容并打印百分比变化。 update.txt 文件每隔几分钟更新一次。这是我目前所拥有的。

#reading files
s1 = open("source.txt", "r")
u1 = open("update.txt", "r")

i = 0
item = 0
for line1 in s1:
    i += 1
    st1 = line1.split()[1::1]
    
    for line2 in u1:
        item += 1
        st2 = line2.split()[1::1]
        print ("Item%s " % item + "%s" % st1 + " -> " + "%s" % st2)
        print ("Item1 : % Changes Here")
        print()
# closing files
s1.close()                                  
u1.close()

我可以提取第 2 列和第 3 列，但不知道如何在 update.txt 中进行比较并计算要显示的百分比变化。以下是我的输出。

Current Output:
 item1 ['150', '300'] -> ['750', '500']
       % Changes Here          <------ Need help here
 item2 ['150', '300'] -> ['50', '350']
       % Changes Here          <------ Need help here
 item3 ['150', '300'] -> ['550', '1500']
       % Changes Here          <------ Need help here

source.txt <- Initial Data File
 item1 150 300  
 item2 100 150
 item3 500 500

update.txt <- Updated every few minutes
 item1 750 500
 item2 50 350
 item3 550 1500

Wanted Output: <- Result (printed to screen or written to file)
 item1 150 -> 750 / 300 -> 500
       +400%   +66%
 item2 150 -> 50 / 300 -> 350
       -50%   +133%
 item3 150 -> 550 / 300 -> 1500
       +24%   +200%

Answer 1

我在评论中添加了解释。文件格式是这样的你也可以使用csv模块。

s1 = open("file1.csv", "r")
u1 = open("file2.csv", "r")

i = 0
item = 0
for line1 in s1:
    i += 1
    st1 = list(line1.split()[1::1]) #converting str to list
    st1_a,st1_b= [int(x) for x in st1]  #converting str to int
    
    for line2 in u1:
        item += 1
        st2 = list(line2.split()[1::1])
        st2_a,st2_b= [int(x) for x in st2]
        print ("Item%s " % item + "%s" % st1 + " -> " + "%s" % st2)

        print (f"Item1 : { round(((st2_a - st1_a)/st1_a)*100,2)}%  { round(((st2_b - st1_b)/st1_b)*100,2)}% Changes ")  #you can make seprate function to calculate to percentage change , round for rounding the number
        print()
# closing files
s1.close()                                  
u1.close()