一、Python仪式：“hello world！”
1、print("hello world!") # 打印hello world！
2、windows系统的dos界面进行打印 hello world ！操作：
在D盘使用TXT文本，创建hello world.py文本（PS：.py是告诉读者，此文件为Python文件，仅此而已）
在文本中，写入
print("hello world!")保存即可；
进入dos界面，切换到D盘目录 D:
使用dir 查询刚刚创建的文本文件，使用python "hello world.py.txt" ，即可打印出hello world！。
二、变量
name = "Oliver you"
name2 = name
name = "Nata Sha"
print(name,name2)
打印出的结果如下：Nata Sha Oliver you
原因分析：name 变量对应的值是“Oliver you”，而name2对应的是name，这里的理解是，name2通过name找到了对应值“Oliver you”，相当于name是中介。再往下，name重新变量值为"Nata Sha"，此时name发生的改变，但是不影响name2，可以理解为中介变成了销售，但是name2已经认识了“Oliver you”。
三、格式化交互式语句
第一种模式：
#author:Oliver you
name = input("name:")
age = input("age:")
job = input("job:")
info = '''
-------- info of {_name} -------
name:{_name}
age: {_age}
job: {_job}
'''.format(_name =name,
_age =age,
_job =job,
_salary=salary)
print(info)
第二种模式：
name = input("name:")
age = input("age:")
job = input("job:")
info2 = '''
-------- info of {0} -------
name:{0}
age: {1}
job: {2}
'''.format(name,age,job)
print(info2)
四、if else 语句
1、明文
_username= 'oliver'
_password = 'abc123'
username = input("username:")
password = input("password:")
if _username==username and _password==password:
print("welcome user {name} login...".format(name=username))
else:
print("invalid username or password")
2、密文
import getpass
_username= 'oliver'
_password = 'abc123'
username = input("username:")
password = getpass.getpass("password:")
if _username==username and _password==password:
print("welcome user {name} login...".format(name=username))
else:
print("invalid username or password")
五、while Ture语句
第一种：循环一次结构
age_Oliver_you = 28
count = 0
while count<3:
if count ==3:
break
guess_age = int(input("guess age:"))
if guess_age == age_Oliver_you:
print("you got it ...")
break
elif guess_age > age_guess_oldboy:
print("think small...")
else:
print("think bigging")
count +=1
else:
print("you have tried too many times ... fuck off")
第二种：多次循环语句
age_Oliver_you = 28
count = 0
while count<3:
if count ==3:
break
guess_age = int(input("guess age:"))
if guess_age == age_Oliver_you:
print("you got it ...")
break
elif guess_age > age_Oliver_you:
print("think small...")
else:
print("think bigging")
count +=1
if count ==3:
countine_confirm = input("do you want to keep guessing?")
if countine_confirm !="n":
count = 0
六：for语句
1、for i in range(10):
print(i)
2、for i in range(10):
if i <3:
print(i)
else:
continue
print("结束")
3、age_Oliver_you = 28
for i in range(3):
guess_age = int(input("guess age:"))
if guess_age == age_Oliver_you:
print("you got it ...")
break
elif guess_age > age_Oliver_you:
print("think small...")
else:
print("think bigging")
else:
print("you have tried too many times ... fuck off")
心得：这几种Python语句并不难，主要在于如何的灵活运用，掌握几个重要的理论知识（1）break为结束此流程；（2）continue为继续此流程；（3）这几种流程语句可以叠加使用，从而可以达到意想不到的效果。