AttributeError：“set”对象没有属性“keys”

Question

我正在尝试将 Unix 秒数从 csv 文件转换为日期和时间，并尝试将输出作为新列写入 csv 文件。我可以转换和打印日期和时间，但我不能将其写入与新列相同的 csv。

AttributeError: 'set' 对象没有属性 'keys'

我尝试用不同的方式写作，但卡住了。我做错了什么？

import pandas as pd

df = pd.read_csv ('C:/New.csv',sep=';')
print (df)

import datetime
import csv


for i in range(0,len(df)):
    row= df.iloc[i]['arrival_unix_seconds']
    a = int(row)
    date = datetime.datetime.utcfromtimestamp(a)
    targetDate = date.strftime("%Y-%m-%d %H:%M:%S")
    #print(targetDate)
    #targetDate.to_csv("b.csv", sep=';', index=False)

with open("New.csv", "a") as inputfile:

title = ["id", "space_id", "arrival_unix_seconds", "departure_unix_seconds", "xml_id", "Arrival_time"]
writer = csv.DictWriter(inputfile, delimiter=';', fieldnames = title)
writer.writerow({"Arrival_time: targetDate"})

样本数据

id;space_id;arrival_unix_seconds;departure_unix_seconds;xml_id;Arrival_time 2950;72729;1619808731;1619809039;22
320;16639;1612627087;1612628433;76
82;3408;1609751088;1609751723;7

Answer 1

试试apply，它比逐行迭代快得多

df['arrival_unix_seconds'] = df.arrival_unix_seconds.apply(lambda x: \
    (datetime.datetime.utcfromtimestamp(int(x))).strftime("%Y-%m-%d %H:%M:%S"))

# Save it like this
pd.to_csv('NEW.csv', index=False)

不是这个

for i in range(0,len(df)):
    row= df.iloc[i]['arrival_unix_seconds']
    a = int(row)
    date = datetime.datetime.utcfromtimestamp(a)
    targetDate = date.strftime("%Y-%m-%d %H:%M:%S")
    #print(targetDate)
    #targetDate.to_csv("b.csv", sep=';', index=False)

with open("New.csv", "a") as inputfile:

title = ["id", "space_id", "arrival_unix_seconds", "departure_unix_seconds", "xml_id", "Arrival_time"]
writer = csv.DictWriter(inputfile, delimiter=';', fieldnames = title)
writer.writerow({"Arrival_time: targetdata"})