使用用户输入向数据框添加列 pandas

Question

如何使用 pandas(python) 中的用户输入添加列。如何修改代码以实现此目的？

sel= str(input("would you like to add a new column to df"))
if sel == "yes":
   name=str(input("Name of new column to df"))
   name=[]
   df= df.append(name)
else:
    print("column not added")

Answer 1

试试这个代码？

import pandas as pd
x=[[1,2,3,4],[5,6,7,8],[9,10,11,12]]
column_name=["Column 1","Column 2","Column 3"]
d=input("Would you like to add columns to your dataframe? ")
if d.lower()=="yes":
    new_columns=[]
    c=input("Add any four numbers to your dataframe, add a ',' after each number: ")
    name=input("Name you column: ")
    list1=str(c).split(",")
    for number in list1:
        number=int(number)
        new_columns.append(number)
    column_name.append(name)
    x.append(new_columns)
    df=pd.DataFrame(x,columns=column_name)
    print(df)
else:
    print("No new columns were added.")
    column_name.append("Column 4")
    df=pd.DataFrame(x,columns=column_name)
    print(df)

Answer 2

你快到了！将附加更改为 .loc。见下文。

df = pd.DataFrame({1: [1, 2, 3], 2: [1, 2, 3]})
sel= str(input("would you like to add a new column to df"))
if sel == "yes":
    name=str(input("Name of new column to df"))
df.loc[:, name] = 'test values'
else:
    print("column not added")

Answer 3

您可以使用：

import numpy as np

sel= str(input("would you like to add a new column to df"))
if sel == "yes":
   name=str(input("Name of new column to df"))
   if name != '':
       df[name] = np.nan     # init to NaN.  You are freely to change this
       print(f"column {name} succesffuly added")
   else:
       print("Name empty. Column not added")
else:
    print("column not added")

这将检查列的输入名称是否为空字符串。如果为空，则不会添加列。如果列名不为空，则列内容将被初始化为NaN。您可以根据自己的喜好更改此初始化值。也会显示一条消息，其中列名也已成功添加。

使用用户输入向数据框添加列 pandas

adding a column to a dataframe using user input pandas

python

user-input

dataframe

pandas

data-science