python基础面试

一、给定一个字符串，将字符串的偶数位的字母替换成*

l = 'hu21w3ad234eww3123478965hjawk1212'
li = []
for i in l:
   li.append(i)

for n in range(len(li)):
   if (n+1) % 2 == 0 and li[n].isdigit():

      li[n] = li[n].replace(li[n], "*")

   else:
      continue

print("".join(li))

二、输入三个整数x,y,z，请把这三个数由小到大输出。

li = []
for i in range(3):
   a = int(input("请输入整数"))
   li.append(a)
li.sort()
print(",".join(li))

三、计算字符串中字符出现的次数

l = 'hu21w3ad234eww3123478965hjawk1212'
d = {}
for i in l:
   d[i] = l.count(i)
print(d)
dn = 0
for n in sorted(d):
   print(
      "%s 出现的次数是%s" % (n, d[n])
   )

四、list中放一个字典，name和age，不改变list的情况下，设计算法让name按照age升序排列。

li = [
   {"name": "xiaoming", "age": 22},
   {"name": "xiaogang", "age": 13},
   {"name": "limin", "age": 19},
   {"name": "wkqlj", "age": 42},
   {"name": "AA", "age": 2}
]
import operator

li.sort(key=operator.itemgetter('age'), reverse=False)
print(li)