2020-2-21(64)

#295、找出字符串中不包含在26个字母中的字母
#方法一

import string
def get_missing_letter(s):
    if not isinstance(s,str):
        return None
    s = s.lower()
    letters = string.ascii_lowercase
    result = set(letters) - set(s)
    return "".join(list(result))
    
print(get_missing_letter("A quick brown for jumps over the lazy dog"))
print(get_missing_letter("A slow yellow fox crawls under the proactive dog"))

#方法二
import string
def get_missing_letter(s):
    if not isinstance(s,str):
        return None
    result = ""
    s = s.lower()
    letters = string.ascii_lowercase
    for i in letters:
        if i not in s:
            result += i
            
    return result

print(get_missing_letter("A quick brown for jumps over the lazy dog"))
print(get_missing_letter("A slow yellow fox crawls under the proactive dog"))

#298、求出列表所有奇数并构造新列表
print([x for x in range(100) if x%2 ==1])

#299、用一行python代码写出1+2+3+10248

print(sum([1,2,3,10248]))

#304、统计一个文本中单词频次最高的10个单词

import re
with open("d:\\2019\\1.txt") as fp:
    content = fp.read()
print(content)
content = re.findall(r"\b[a-zA-Z]+\b",content)
print(content)

word_dict = {}
for word in content:
    if word not in word_dict:
        word_dict[word] = 1
    else:
        word_dict[word] += 1
print(word_dict)
sort_word_dict = sorted(word_dict.items(),key=lambda x:x[1],reverse=True)
print(dict(sort_word_dict[:10]))

#305、请写出一个函数满足以下条件
#该函数的输入是一个仅包含数字的list,输出一个新的list，
#其中每一个元素要满足以下条件：
#1、该元素是偶数
#2、该元素在原list中是在偶数的位置(index是偶数)

def get_list(l):
    if not isinstance(l,list):
        return None
    result = []
    for i in range(len(l)):
        if i%2==0 and l[i]%2==0:
            result.append(l[i])
    return result
    
print(get_list([1,2,3,4,8,6,8,10]))

#306、用一行代码生成[1,4,9,16,25,36,49,64,81,100]

print([x**2 for x in range(1,11)])

#307、给定一个任意长度数组，实现一个函数
#让所有奇数都在偶数前面，而且奇数升序排列，偶数降序排序，
#如字符串’1982376455’,变成’1355798642’

def sortString(s):
    odd_list=[]  #偶数序列
    even_list=[] #奇数序列
    for i in s:
        if int(i)%2==0:
            odd_list.append(i)
        else:
            even_list.append(i)
    odd_list=sorted(odd_list,reverse=True)
    even_list=sorted(even_list)
    result = even_list + odd_list
    return "".join(result)
    
print(sortString('1982376455'))

#308、找出一个整数数组中的第二大数

l = [1,-4,8,3,9,2,10]
print(sorted(l,reverse=True)[1])