python快速入門1

記錄python若干功能特點，幫助快速瞭解python語法

 

 

#!/usr/bin/env python

# 驗證若干python功能

import pandas as pd
import numpy as np
import time
import datetime

from string import Template

if __name__ == "__main__":
    # 格式化字符串，帶參數名稱
    tmpl = Template("Hello, $who! $what enough for ya?")
    str2 = tmpl.substitute(who="Mars", what="Dusty")
    print(str2)

    # 格式化一個字符串...直接使用外部變量
    day = 20230308
    str3 = f""" today is {day} . """
    print("str3:", str3)

    # 格式化一個字符串，通過傳入對應位置參數賦值
    str4 = " paraA:{} , paraB:{} , paraC:{}, paraD:{}"
    str5 = str4.format("A", "B", "C", day)
    print("str4:", str4)
    print("str5:", str5)

    # 用get方法訪問字典，可以避免程序出現錯誤或異常
    dic1: dict = {'name': 'henry', 'age': "123"}
    print("dic1.get name:", dic1.get('name', "name_bk"))
    print("dic1.get name2:", dic1.get('name2', "name_bk"))

    # 用作布爾表達式（如用作if語句中的條件）時，下面的值都將被解釋器視爲假：
    # False  None  0  ""  ()  []   {}
    if None:
        print("true")
    else:
        print(None)

    # 程序裏面的斷言
    age = -1
    assert (0 < age < 100, "The age must be realistic")
    print("age:", age)