如何遍历 csv 文件并用 python 字典替换其中的值

How can I loop through a csv file and replace values in it with a python dictionary

这是我的字典{'0':'Denver', '1':'Chicago', '2':'Maryland'}

在我的 csv 文件中 0 1 1 0 2 2 3 2 我想将 CSV 文件中的数字更改为字典中的值: 0 芝加哥 1 丹佛 2 马里兰州 3 马里兰州

d = {'0':'Denver', '1':'Chicago', '2':'Maryland'}

# we'll start by creating a new file to write the output to
with open("output_filename.csv", "w+") as out_file:
    # So the first piece is reading the file in python
    with open("filename.csv") as in_file:
        # next you'll want to loop over each line
        for line in in_file:
            # Now we can split the string into elements by the whitespce
            line_list = line.split(" ")
            # line_list = ['0', '1', '1', '0', '2', '2', '3', '2']
            # we can loop over the list taking alternating elements and looking them up
            result = " ".join([d[item] if index % 2 else item for index, item in enumerate(line_list)])
            out_file.write(result)

真正的“工作”发生在这一行: result = " ".join([d[item] if index % 2 else item for index, item in enumerate(line_list)])

enumerate returns 我们遍历 line_list 时的索引和值 所以 (0, '0'), (1, '1'), (2, '1') ...

然后车工正在使用模 % 来查看除以 2 时的余数(即如果索引为 0、2、4...)并使用字典查找如果 不是 的值(即索引 1、3、5...)