Python循环遍历csv列表并检查值？

Question

我有五个 .csv 文件，它们具有相同顺序的相同字段，需要这样处理:

获取文件列表

将每个文件变成一个数据框

检查一列字母数字组合是否具有特定值(每个文件不同)例如:检查数字 PT333在 column1对于文件名 data1 :

column1   column2    column3    
PT389     LA       image.jpg
PT372     NY       image2.jpg

如果该列具有特定值，则打印它具有的值以及我分配给该文件的文件名/变量名，然后将该数据框重命名为 output1

我试图这样做，但我不知道如何让它循环并为每个文件做同样的事情。
目前它返回数字，但我也希望它返回数据框名称，我还希望它遍历所有文件(a 到 e)以检查 numbers 中的所有值。列表。

这就是我所拥有的:

import os
import glob
import pandas as pd
from glob import glob
from os.path import expanduser

home = expanduser("~")
os.chdir(home + f'/files/')

data = glob.glob('data*.csv')
data

# If you have tips on how to loop through these rather than 
# have a line for each one, open to feedback
a = pd.read_csv(data[0], encoding='ISO-8859-1', error_bad_lines=False)
b = pd.read_csv(data[1], encoding='ISO-8859-1', error_bad_lines=False)
c = pd.read_csv(data[2], encoding='ISO-8859-1', error_bad_lines=False)
d = pd.read_csv(data[3], encoding='ISO-8859-1', error_bad_lines=False)
e = pd.read_csv(data[4], encoding='ISO-8859-1', error_bad_lines=False)
filenames = [a,b,c,d,e]
filelist= ['a','b','c','d','e']

# I am aware that this part is repetitive. Unsure how to fix this,
# I keep getting errors
# Any help appreciated
numbers = ['PT333', 'PT121', 'PT111', 'PT211', 'PT222']
def type():
    for i in a.column1:
        if i == numbers[0]:
            print(numbers[0])
        elif i == numbers[1]:
            print(numbers[1])
        elif i == numbers[2]:
            print(numbers[2])
        elif i == numbers[3]:
            print(numbers[3])
        elif i == numbers[4]:
            print(numbers[4])
type()

也很乐意接受关于如何减少重复代码并使事情更顺畅的任何 build 性批评。 TIA

Answer 1

试试这个

for file in glob.glob('data*.csv'):       # loop through each file
    df = pd.read_csv(file,                # create the DataFrame of the file
             encoding='ISO-8859-1', 
             error_bad_lines=False)
    result = df.where( \                  # Check where the DF contains these numbers
                 df.isin(numbers)) \
                .melt()['value'] \        # melt the DF to be a series of 'value'
                .dropna() \               # Remove any nans (non match)
                .unique().tolist()        # Return the unique values as a list.
    if result:                            # If there are any results 
        print(file, ', '.join(result)     # print the file name, and the results

如果您要复制和粘贴代码，请删除注释和尾随空格。为 result行，以防您遇到 SyntaxError .

如前所述，您应该也可以在没有 DataFrame 的情况下执行相同操作:

for file in glob.glob('data*.csv'):
    data = file.read()
    for num in numbers:
        if num in data:
            print(file, num)