python基础练习（五）

s = eval(input("请输入一个数字："))
ls = [0]
for i in range(65,91):
    ls.append(chr(i))
print("输出大写字母：{}".format(ls[s]))

s = input("请输入一个十进制数：")
num = int(s)
print("转换成二进制数是：{0:b}".format(num))

import jieba
s = input("请输入一个中文字符串，包含标点符号：")
m =len(jieba.lcut(s))
print("中文词语数：{}".format(m))

import turtle
turtle.color("red","yellow")
turtle.begin_fill()
for i in range(36):
    turtle.fd(200)
    turtle.left(170)
turtle.end_fill()

fo = open("PY202.txt","w")
def prime(num):
    for i in range(2,num):
        if num%i==0:
            return False
    return True    
ls = [51,33,54,56,67,88,431,111,141,72,45,2,78,13,15,5,69]
lis = []
for i in ls:
    if prime(i) == False:
        lis.append(i)#此处为一行代码
fo.write(">>>{}，列表长度为{}".format(lis,len(lis)))
fo.close()

fi=open("arrogant.txt","r")
fo=open("arrogant-sort.txt","w")
txt=fi.read()
d = {}
for s in txt:
    d[s]=d.get(s,0)+1
del d["\n"]
ls =list(d.items())
ls.sort(key=lambda x:x[1],reverse=True)
for i in range(10):
    fo.write("{}:{}\n".format(ls[i][0],ls[i][1]))
fi.close()
fo.close()

对文件读取是 若是逐行操作直接for line in fi 循环即可，对文件逐字符进行操作：定义txt，运用函数fi.read（）
for s in txt进行操作