python - 如何比较第一列和第二列

Question

我的功课遇到问题。我的目标是比较第一列第一行和第二列第二行。

我是 Pandas 新手，所以我尝试在互联网上浏览答案，但遗憾的是没有。我想到了一种方法，即将 pandas 转换为数组，并将第一列存储到第一个数组，第二列存储到第二个数组。

first_array = [4,10,17,24,82,93,35,40,49,71,78]
last_array = [9,16,23,29,89,97,39,48,57,77,85]

之后我弹出了first_array的第一个数字，即4，然后在最后一个数字中插入一个0，如下所示

first_array = [10,17,24,82,93,35,40,49,71,78, 0]
last_array =  [ 9,16,23,29,89,97,39,48,57,77,85]

还有一点 for 循环

if first_array < last_array:
   print ("===")

但看来我的逻辑是正确的，但我期望的输出有一点错误

['10', '17', '24', '82', '93', '35', '40', '49', '71', '78', '0']
['9', '16', '23', '29', '89', '97', '39', '48', '57', '77', '85']
===
['17', '24', '82', '93', '35', '40', '49', '71', '78', '0']
['16', '23', '29', '89', '97', '39', '48', '57', '77', '85']
['24', '82', '93', '35', '40', '49', '71', '78', '0']
['23', '29', '89', '97', '39', '48', '57', '77', '85']
['82', '93', '35', '40', '49', '71', '78', '0']
['29', '89', '97', '39', '48', '57', '77', '85']
['93', '35', '40', '49', '71', '78', '0']
['89', '97', '39', '48', '57', '77', '85']
['35', '40', '49', '71', '78', '0']
['97', '39', '48', '57', '77', '85']
===
['40', '49', '71', '78', '0']
['39', '48', '57', '77', '85']
['49', '71', '78', '0']
['48', '57', '77', '85']
['71', '78', '0']
['57', '77', '85']
['78', '0']
['77', '85']
['0']
['85']
===

第一个“=== 10 不是 < 9”，这让我思考。我错过了什么？预先感谢您。

这是我的代码片段。 print(join_tag) 是我需要的输出。

normalized_text = []
first_array = [10,17,24,82,93,35,40,49,71,78, 0]
last_array =  [ 9,16,23,29,89,97,39,48,57,77,85]
for word in normalized_text:
    join_tag = ' '.join(word)
    print (join_tag)
    if first_array < last_array:
        print ('===')
        first_array.pop(0)
        last_array.pop(0)

预期输出为

['10', '17', '24', '82', '93', '35', '40', '49', '71', '78', '0']
['9', '16', '23', '29', '89', '97', '39', '48', '57', '77', '85']
['17', '24', '82', '93', '35', '40', '49', '71', '78', '0']
['16', '23', '29', '89', '97', '39', '48', '57', '77', '85']
['24', '82', '93', '35', '40', '49', '71', '78', '0']
['23', '29', '89', '97', '39', '48', '57', '77', '85']
['82', '93', '35', '40', '49', '71', '78', '0']
['29', '89', '97', '39', '48', '57', '77', '85']
['93', '35', '40', '49', '71', '78', '0']
['89', '97', '39', '48', '57', '77', '85']
['35', '40', '49', '71', '78', '0']
['97', '39', '48', '57', '77', '85']
===
['40', '49', '71', '78', '0']
['39', '48', '57', '77', '85']
['49', '71', '78', '0']
['48', '57', '77', '85']
['71', '78', '0']
['57', '77', '85']
['78', '0']
['77', '85']
['0']
['85']
===

Answer 1

如果我没理解你的问题，你想比较 4 和 16，对吗？

如果是这样，将数据放回到数据框中:

import numpy as np
import pandas as pd

first_array = np.array([4,10,17,24,82,93,35,40,49,71,78])
last_array = np.array([9,16,23,29,89,97,39,48,57,77,85])
df = pd.DataFrame(np.vstack((first_array, last_array)))

然后:

df.iloc[0, 0] < df.iloc[1, 1]

将比较 4 < 16

比较它们:

for i in range(len(df.columns)-1):
    print(df.iloc[0, i] < df.iloc[1, i+1])