DataFrame(data) # Using DataFrame.insert() to add a column df.insert(2, "Age", [21, 23, 24, 21], True) # Observe the result print(df) Python Copy输出:方法#3:使用Dataframe.assign()方法这个方法将创建一个新的数据框架,并在旧的数据框架中添加一个新的列。
http://pandas.pydata.org/pandas-docs/stable/dsintro.html#column-selection-addition-deletion 数据准备 随机生成8*3的DataFrame df1,筛选 a 列大于0.5的行组成df2,作为我们的初始数据。 import numpy as np import pandas as pd print pd.__version__ #0.19.2 np.random.seed(0) df1 = pd.DataFrame(np...
# Using DataFrame.insert() to add a column df.insert(2,"Age",[21,23,24,21],True) # Observe the result df 输出: 方法#3:使用Dataframe.assign()方法此方法将创建一个新数据帧,并在旧数据帧中添加一个新列。 Python3实现 # Import pandas package importpandasaspd # Define a dictionary containing...
Note:You can usecolumn_positionto add the column in any preferable position in the data frame. For example, if you want to add it in position 3, then the code will be:df.insert(3, “patient_name”, names) Result: Method 3: Using theDataframe.assign()method This method allows you to...
从Pandas 0.16.0 开始,您还可以使用assign ,它将新列分配给 DataFrame 并返回一个新对象(副本)以及除新列之外的所有原始列。 df1 = df1.assign(e=e.values) 根据此示例 (还包括assign函数的源代码),您还可以包含多个列: df = pd.DataFrame({'a': [1, 2], 'b': [3, 4]}) >>> df.assign(...
Pandas Add Column with Constant Value to DataFrame You have an existing DataFrame where you need to add an additional column with the same constant value for every row.df["Discount_Percentage"]=10will add the “Discount_Percentage” column and set every row with a constant value10. ...
df = pd.DataFrame() print (df) 输出 Empty DataFrame Columns: [] Index: [] 说明:在上面的代码中, 首先, 我们导入了别名为pd的pandas库, 然后定义了一个名为df的变量, 该变量包含一个空的DataFrame。最后, 我们通过将df传递到打印文件中进行打印。
In the above sections, you have seen how to add while creating a DataFrame. Sometimes it’s not possible to know the column names up-front and you may need to add names to the existing DataFrame. In this example, thecolumnsattribute is used to assign a new list of column names (column...
Example 1: Append New Variable to pandas DataFrame Using assign() Function Example 1 illustrates how to join a new column to a pandas DataFrame using the assign function in Python. Have a look at the Python syntax below: data_new1=data.assign(new_col=new_col)# Add new columnprint(data_...
DataFrame(mydata) df # 输出 Column1 Column2 0 1 a 1 2 b 2 3 c 指定行索引: # 指定行索引 df.index = ['row1', 'row2', 'row3'] df # 输出 Column1 Column2 row1 1 a row2 2 b row3 3 c 使用另一个 Series 或数组作为索引: # 使用另一个 Series 或数组作为索引 index_series ...