python基础

1. python 资料:

python3在线文档：http://tool.oschina.net/apidocs/apidoc?api=Python%2Freference

python2.7在线文档：http://tool.oschina.net/apidocs/apidoc?api=python2.7.3

python3博客地址: http://www.liaoxuefeng.com

2. 

# 1. 输入
print("****** abc *******",end="")
print("****** 123 *******") # == > ****** abc ************* 123 ******* 备注: end=""不换行
# 2. 运算符
a = input("Please input the first number:")
b = input("Please input the second number:")
print("The result %s + %s = %d"%(a,b,(int(a)+int(b)))) # == > The result 10 + 23 = 33
# 3. list
arrayList = ["abc","123",[123,"345"],[["se","df"]]]
a1 = arrayList[0]
a2 = arrayList[2][0]
a3 = arrayList[3][0][0]
print("a1=%s\na2=%d\na3=%s"%(a1,a2,a3)) # == > a1=abc  a2=123  a3=se

# 4. 计算体重
a4 = 1.75
a5 = 80.5
BMI = a4 / a5**a5
if BMI > 32 :
    print("严重肥胖")
elif BMI > 28:
    print("过重")
elif BMI < 18.5:
    print("过轻")
else :
    print("正常")
# == > 过轻

# 5. 循环遍历
names = ["a","b","c"]
for name in names:
    print("name=%s"%name) # == > name=a  name=b  name=c


sum = 0
for x in [1,23,3,3,3,3,3,0,5,5,5,5]:
    sum += x
print("sum=%d"%sum) # == > sum=59

# 6. 计算1-100整数的和
listArray = list(range(101))
sum6 = 0
for s6 in listArray:
    sum6 += s6
print("0~100的整数和:%d",sum6) # == > 0~100的整数和:%d 5050
# 7. while循环计算
sum7 = 0
a7 = 0
while a7 < 101:
    sum7 = sum7 + a7
    a7 += 1
print("while循环:%d",sum7) # == > while循环:%d 5050

# 练习请利用循环依次对list中的每个名字打印出Hello, xxx!：
L = ["Python","Objective-C","Swift"]
for L1 in L:
    print("Hello,%s"%L1) # == > Hello,Python  Hello,Objective-C  Hello,Swift
# 8.字典 
dictionary = {"WebApp":"Python","iOS":"Objective-C","Android":"java"}
dict8 = dictionary["WebApp"] # 拿到字典中key为WebApp对应的Value
print("拿到字典中key为WebApp对应的value:%s"%dict8) # == > 拿到字典中key为WebApp对应的value:Python
bool = "iOS" in dictionary # 判断key是否在字典中
print("判断key是否在字典中不存在%d"%bool) # == > 判断key是否在字典中不存在1
a8 = dictionary.get("PHP",-1) # 字典中的key不存在的话输出-1
print("字典中的key是否存在不存在输出自己设定的值:%d"%a8) # == > 字典中的key是否存在不存在输出自己设定的值:-1
s8 = dictionary.pop("iOS")
print("用pop删除key对应的value为%s"%s8) # == > 用pop删除key对应的value为Objective-C
# 9.set:set和dict类似，也是一组key的集合，但不存储value。由于key不能重复，所以，在set中，没有重复的key
s = set(["1","2","3"])
print("打印一个set",s) # == > 打印一个set {'2', '1', '3'}
s = set(["1","2","3","3","2","1"])
print("set可以去重",s) # == > set可以去重 {'2', '1', '3'}
# add(key)方法可以添加元素到set中，可以重复添加，但不会有效果
s.add(4)
print("输出添加元素后的set",s) # == > 输出添加元素后的set {'2', 4, '1', '3'}
# 通过remove(key)方法可以删除元素：
s.remove(4)
print("输出移除后的代码",s) # == > 输出移除后的代码 {'2', '1', '3'}
s1 = set([1,2,3])
s2 = set([2,3,4])
s3 = s1 & s2
print("交集结果",s3) # == > 交集结果 {2, 3}
s4 = s1 | s2
print("并集结果",s4) # == > 并集结果 {1, 2, 3, 4}
# 10.排序
sortArray = ["3","2","1"]
sortArray.sort()
print("排序后的数组:",sortArray) # == > 排序后的数组: ['1', '2', '3']
# 练习: 九九乘法表
m = 1
while m <= 9:
    n = 1
    while n <= m:
        print("%d*%d=%-2d "%(n,m,m*n),end="")
        n += 1
    print("")
    m += 1

#1*1=1
#1*2=2  2*2=4
#1*3=3  2*3=6  3*3=9
#1*4=4  2*4=8  3*4=12 4*4=16
#1*5=5  2*5=10 3*5=15 4*5=20 5*5=25
#1*6=6  2*6=12 3*6=18 4*6=24 5*6=30 6*6=36
#1*7=7  2*7=14 3*7=21 4*7=28 5*7=35 6*7=42 7*7=49
#1*8=8  2*8=16 3*8=24 4*8=32 5*8=40 6*8=48 7*8=56 8*8=64
#1*9=9  2*9=18 3*9=27 4*9=36 5*9=45 6*9=54 7*9=63 8*9=72 9*9=81