活動地址：CSDN21天學習挑戰賽
1,學習目標
提示：可以添加學習目標
例如： 一周掌握 Python 入門知識
2,學習內容
提示：可以添加要學的內容
例如：
A,掌握 Python 基本語法
B,掌握 Python 列表、字典、Usage of collection types such as tuples
C,掌握 Python 函數
D,掌握 Python 常用模塊
E, 掌握 Python 模塊與包
F,掌握 Python 類與對象
3,學習時間
Take out two hours a day
4,學習產出
CSDN技術博客 每天一篇
# 案例1
# x = 10
# y = 20
# print(10 + 20)
# print(x + y)
# print(x - y)
# print(x * y)
# print(x / y)
# 案例2
# x = 10
# print(id(x))
# x = 100
# print(id(x))
# 變量命名規范
a1 = 10 # 不能是1a
x = 10
X = 100
# 姓名 = "yuan"
# print(姓名)
# 見名知意
age = 20
firstName = "lin"
secondName = "hu"
first_name = "li"
# 一 關於注釋
# The content of the comment is not to bepythonWhat the interpreter executes,For people to make annotations 這是一個單行注釋
''' 這是一個多行注釋！ Use three single quotes or three double quotes to distinguish '''
# 二 About statement splitting symbols
# x = 10;y = 20 # Semicolons are supported as delimiters,但是不推薦
a = 1
b = 2 # A newline is recommended as the delimiter
# 三 關於縮進 流程控制語句
# 四 pep8規范
c = 20 # control+alt+l ： Formatting shortcut
def foo():
pass
def bar():
pass
x = 100
# python內置函數：type: View the type of a data
print(type(x)) # <class 'int'>
f = 3.1415926
print(type(f)) # <class 'float'>
a = 3.14E3 # Exponential expression： E3即 10的三次方
print(a)
# 布爾類型 ： True False
print(2 == 3) # The return value is a boolean value
print(2 < 3) # True
print("yuan" == "yuan") # True
print(type(1 > 2)) # <class 'bool'>
print("1" == 1)
# 零值： There is a boolean for each data typeFalse的值
# 整型的零值：0 字符串的零值："" The zero value of a list is the empty list The zero value of a dictionary is an empty dictionary
# 內置函數: bool
print(bool(1))
print(bool(100))
print(bool(-1))
print(bool(0))
print(bool("False"))
print(bool("0"))
print(bool(""))
print(bool([]))
print(bool({
}))
x = 10
b = True
# 一 創建一個字符串
s = "hello world" # Strings are marked with double or single quotes
print(s)
# 二 字符串的轉義符 \: 1. Convert some common symbols to special symbols ,比如\n 2. Convert some special symbols to normal symbols
s2 = 'i\'m yuan! \ni\'m a teacher!'
print(s2)
path = "E:\s32\day02\\next"
print(path)
# 三 長字符串
s3 = " 杜甫 \n白日依山盡 \n黃河入海流"
print(s3)
s4 = ''' 杜甫 白日依山盡 黃河入海流 '''
s5 = """ 請選擇你的操作 1 購買商品 2 結算 3 退出 """
print(s5)
# 四 字符串的格式化輸入
name = "rain"
age = 23
gender = "男"
# The so-called template or format string： Embed a dynamically changing value somewhere in a string.
# s6 = "姓名 yuan.年齡 22.性別 男."
# 占位符號 %s：Take place for the string %d：Places place for decimal integer numbers %f: Place placeholders for floating point types
s6 = "姓名：%s.年齡：%d.性別：%s" % (name, age, gender)
# s6 = "姓名：rain.年齡：23.性別：男"
print(s6)
s = "hello world!"
# A string is composed of several characters in sequence
# Indexing operations on sequence types： 通過索引獲取值 （支持正負索引） 語法格式 數據對象[索引]
print(s[4])
print(s[6])
print(s[-7])
print(s[-1])
# Slicing operations on sequence types：切片操作 獲取多個值 語法格式 數據對象[開始索引：結束索引:step=1]
# 特點1 左閉右開 顧頭不顧尾
# 特點2 ：The step size defaults to 1,That is, cutting one by one from left to right
print(s[0:5])
print(s[6:10])
print(s[6:11])
print(s[6:]) # The default to the right of the colon means that it is taken to the end
print(s[:5]) # The left side of the colon defaults to the secondary index0開始
print(s[:]) # 完整切片
print("s[5:0]:::", s[5:0]) # Match from left to right
print(s[-5:]) # orld!
print(s[-6:-1]) # world
print(s[-3:-5]) # 結果為空
# The step size parameter is positive：Represents cutting from left to right Cut from right to left for negative numbers
# 步長為 -1 : Cut one by one from right to left
print(":::", s[0:5:1])
print(":::", s[0:5:-1])
print(":::", s[4::-1]) # olleh
print(":::", s[::-1]) # !dlrow olleh
# 步長為 2： Take one every other from left to right
print(":::", s[::2])
# Sequence type judgment operation：in 判斷 返回一個布爾值
print("yuan" in "hello yuan")
print("yuan" not in "hello yuan")
print("rain" in "hello yuan")
print("yua" in "hello yuan")
print("yuan hello" in "hello yuan")
# Concatenation of sequence types： 拼接 使用 +
s1 = "hello "
s2 = " yuan"
print(s1 + s2)
# 補充
print("*"*100)
# 內置方法： 數據對象.方法()
# 字符串內置方法： String data object.方法()
# ******************************************** upper方法 lower方法 ********************************************
# 案例1
s = "HELLO"
s_upper = s.upper()
print(s_upper)
print(s)
# 案例2：變量的重新賦值
# s = "hello"
# s = s.upper()
# ******************************************** startswith endswith ********************************************
s1 = "hello yuan"
# ret = s1.startswith("hello") # 返回一個布爾值
ret = s1.endswith("uan") # 返回一個布爾值
print(ret, type(ret)) # True <class 'bool'>
# ******************************************** isdigit: 判斷是否是數字字符串 ****************************************
ret1 = 10 + 20
ret2 = "10" + "20"
print(ret1, type(ret1)) # 30 int
print(ret2, type(ret2)) # "1020" str
print("hello".isdigit()) # False
print("100".isdigit()) # True
print("100個".isdigit()) # False
# ******************************************** strip方法：去除兩端空格 ************************************************
s2 = " yuan "
ret3 = s2.strip() # 去除兩端空格 ”yuan“
print(ret3)
print(ret3 == "yuan")
# ******************************************** 字符串分割：split 字符串拼接join ****************************************
s = "北京,上海,深圳,廣州" # []
ret4 = s.split(",") # Convert a string to a list
print(ret4) # ['北京', '上海', '深圳', '廣州'] ----> "北京;上海;深圳;廣州"
ret5 = "---".join(ret4)
print(ret5) # 北京---上海---深圳---廣州
# 計算運算符
x = 9
print(10 / 3)
print(10 % 4)
print(x % 2 == 0)
# 比較運算符 > < == >= <=
print(2 == "2") # False
print(2 != "2") # True
print(2 > 5) # False
# 賦值運算符 = +=
a = 10
a += 1 # a = a + 1 # 自加一
print(a)
# 邏輯運算符 與運算 and 或運算：or 非運算 not
user = "yuan"
pwd = 123
print(user == "yuan" and pwd == 123) # True
# print("OK")
# name = "yuan"
# age = 22
# print(name)
# print(name,age,sep=",")
# print(111,end=";")
# print(222)
# 輸入函數 inputAccepted must be a string
# name = input("請輸入一個姓名：") # To use the user to enter a value at the terminal
# age = input("請輸入一個年齡：") # To use the user to enter a value at the terminal
# print("姓名：%s 年齡：%s" % (name, age))
# 案例2
a = input("num1>>>") # "20"
b = input("num2>>>") # "30"
# print(int(a)) # Convert a numeric string to an integer
print(int(a) + int(b)) # Convert a numeric string to an integer
# 順序執行
# print("OK")
# print("OK")
# print("OK")
# 分支語句之if語句
''' 在python中用:+Indentation indicates the body of a statement # 單分支語句 if 表達式: 語句1 語句2 語句3 # 雙分支語句 if 表達式: 語句1 語句2 語句3 else: 語句1 語句2 語句3 # 多分支語句 if 表達式1: 語句1 語句2 語句3 elif 表達式2: 語句1 語句2 語句3 elif 表達式3: 語句1 語句2 語句3 ... else: 語句1 語句2 語句3 '''
# 案例1
# if 2 > 1:
# print("ok1")
# print("ok2")
# print("ok3")
# 案例2: 單分支語句
# user = "rain"
# pwd = 123
#
# if user == "yuan" and pwd == 123:
# print("登錄成功！")
#
# print("程序結束！")
# 案例3：雙分支語句
# user = input("請輸入用戶名：")
# pwd = input("請輸入密碼：") # ”123“
#
# if user == "yuan" and pwd == "123":
# print("登錄成功！")
# else:
# print("用戶名或者密碼錯誤")
#
# print("程序結束！")
# 案例4：判斷成績
# score = int(input(">>>"))
#
# if score > 100 or score < 0:
# print("非法輸入")
# elif score >= 90:
# print("成績優秀")
# elif score >= 80:
# print("成績良好")
# elif score >= 60:
# print("成績及格")
# else:
# print("成績不及格")
# 案例5
content = input(">>>")
# 判斷是否是數字字符串
if content.isdigit():
score = int(content)
# judging results
if score > 100 or score < 0:
print("非法輸入")
elif score >= 90:
print("成績優秀")
elif score >= 80:
print("成績良好")
elif score >= 60:
print("成績及格")
else:
print("成績不及格")
else:
print("請輸入一個數字")
# while：條件循環 for：遍歷循環
''' while 表達式: 循環語句體 語句 '''
# 案例1：無限循環
# while 1:
# # print("OK")
# score = int(input(">>>"))
#
# if score > 100 or score < 0:
# print("非法輸入")
# elif score >= 90:
# print("成績優秀")
# elif score >= 80:
# print("成績良好")
# elif score >= 60:
# print("成績及格")
# else:
# print("成績不及格")
# print("程序結束！")
# 案例2：循環打印1-100
# count = 0 # 初始變量
# while count < 100: # 判斷表達式
# # print("OK")
# count += 1 # count = count+1 步進語句
# print(count) # 循環語句體
#
# print("程序結束！")
# 案例3： 計算1+2+3+...+100
# count = 0 # 初始變量
# ret = 0
# while count < 100: # 判斷表達式
# # print("OK")
# count += 1 # count = count+1 步進語句
# # print(count) # 循環語句體
# ret += count # ret = ret+count
#
# print(ret)
# 案例4：打印1-100中所有的偶數
# count = 0 # 初始變量
# ret = 0
# while count < 100: # 判斷表達式
# # print("OK")
# count += 1 # count = count+1 步進語句
# if count % 2 == 0:
# # count是一個偶數
# print(count)
# 案例5：
count = 0 # 初始變量
ret = 0
while count < 100: # 判斷表達式
# print("OK")
count += 1 # count = count+1 步進語句
print(count)
if count == 88:
break # 退出整個while循環
The program randomly builds a number within a certain range as a guess,由用戶猜測此數字.用戶每猜測一次,由系統提示猜測結果：太大了、Too small or guessed right,Until the user guesses the result correctly or the number of guesses runs out, it fails.
設定一個理想數字比如：66,
讓用戶三次機會猜數字,如果比66大,則顯示猜測的結果大了;
如果比66小,則顯示猜測的結果小了;
只有等於66,顯示猜測結果正確,退出循環.
最多三次都沒有猜測正確,退出循環,並顯示‘都沒猜對,繼續努力’.
cnt = 0
realNum = random.randint(0,10) # randint(0,10)的邊界值, 左右邊界的0和10都是可以取到的.
realNum = 66
while cnt < 3:
num = int(input("請輸入您猜的數字:"))
cnt += 1
if num < realNum:
print("猜小了")
elif num > realNum:
print("猜大了")
else:
print("猜對了！")
break
if cnt == 3:
print("三次機會已經用完！")
