python作业2

一维列表分为二维列表

def matrix(data,nrow,ncol):
    result = [[data[i] for i in range(j,j+ncol)] for j in range(0,nrow*ncol,ncol)]
    return result
matrix(data=[1,2,3,4,5,6],nrow=3,ncol=2) #= [[1,2],[3,4],[5,6]]

二维列表合为一位列表

def flat(nestedlist):
    outcome = [j for i in nestedlist for j in i]
    return outcome
flat([[1,2,3],[4,5,6],[7,8,9]])# = [1,2,3,4,5,6,7,8,9]

输出单位矩阵列表

def identity(nrow):
    result = [ [int(i==j) for i in range(nrow)] for j in range(nrow)] 
    return result
identity(3)# = [[1,0,0],[0,1,0],[0,0,1]] 

输出两个字符串相同的字符并大写

x = "trokday"
y = "smuodtay"
z=''.join([ i for i in x if i in y ]).upper()
print(z) # TODAY

一个数a，输出比a小的所有2^x×3^y×5^z的数的列表

def decompose(n):
    answer = [2**x*3**y*5**z for x in range(n) for y in range(n) for z in range(n) if 2**x<=n and 3**y <=n and 5**z<=n ]
    answer.sort()
    answer=answer[0:n]
    return answer
decompose(3)  #= [1,2,3]  

是否为回文字符串

def recycle(string):
    if string==string[::-1]:
        return "YES"
    else:
        return "NO"
recycle('abcba') #  "YES"  # 'NO'

类似二进制的列表转十进制

def binary(lis):
    answer = int(''.join([str(i) for i in lis]),2)
    return answer 
binary([1,0,1]) #= 5