python pandas 构造空的DataFrame,Series对象

 

有时候根据工作需要，需要构造空的DataFrame, Series对象

#!/usr/bin/evn python

import numpy as np
import pandas as pd



df_empty = pd.DataFrame({"empty_index":[]})
print("df_empty:",df_empty)

if df_empty.empty:
    print("df_empty is empty")  # df_empty is empty
else:
    print("df_empty is not empty")

ser_empty = pd.Series({"empty_index":[]})
print("ser_empty:",ser_empty)
print("len(ser_empty):", len(ser_empty))

if ser_empty.empty:
    print("ser_empty is empty")
else:
    print("ser_empty is not empty") # ser_empty is not empty

# 创建一个空的series对象，并指它的元素类型是float64
ser_empty2 = pd.Series([], dtype='float64')
print("ser_empty2:",ser_empty2)
if ser_empty2.empty:
    print("ser_empty2 is empty") # ser_empty2 is empty
else:
    print("ser_empty2 is not empty")

E:\remote_project\lianghua2023\monitor\venv\Scripts\python.exe E:/remote_project/lianghua2023/monitor/app/henry/helloC.py
df_empty: Empty DataFrame
Columns: [empty_index]
Index: []
df_empty is empty
ser_empty: empty_index    []
dtype: object
len(ser_empty): 1
ser_empty is not empty
ser_empty2: Series([], dtype: float64)
ser_empty2 is empty

Process finished with exit code 0