46 Simple Python Exercises-Very simple exercises

46 Simple Python Exercises-Very simple exercises

4、Write a function that takes a character (i.e. a string of length 1) and returns True if it is a vowel, False otherwise.

#编写一个函数，该函数接受一个字符（即长度为1的字符串），如果是元音，则返回true，否则返回false。

def if_vowel(a):
    a=a.lower()
    if a in('a','e','i','o','u'):
        return True
    else:
        return False
print(if_vowel('A'))

5、Write a function translate() that will translate a text into "r�varspr�ket" (Swedish for "robber's language"). That is, double every consonant and place an occurrence of "o" in between. For example, translate("this is fun") should return the string "tothohisos isos fofunon".

编写一个函数translate（），将文本转换为“r varspr ket”（瑞典语表示“强盗的语言”）。也就是说，将每个辅音加倍，并在中间加上“o”。例如，translate（“this is fun”）应该返回字符串“totohohisos isos fofunon”。

def if_vowel(a):
    if a in('a','e','i','o','u'):
        return True
    else:
        return False
def translate(string):
    char_list=[]
    for char in string:
        if if_vowel(char) or char==" ":
            char_list.append(char)
        else:
            char_list.append(char+'o'+char)
    return "".join(char_list)
print(translate("this is fun"))

6、Define a function sum() and a function multiply() that sums and multiplies (respectively) all the numbers in a list of numbers. For example, sum([1, 2, 3, 4]) should return 10, and multiply([1, 2, 3, 4]) should return 24.
定义一个函数sum（）和一个函数multiple（），分别对数字列表中的所有数字求和和和相乘。例如，SUM（[1，2，3，4]）应返回10，乘法（[1，2，3，4]）应返回24。

def sum(sum_list):
    sum1 = 0
    for b in sum_list:
        sum1 += b
    return sum1
print(sum([1,2,3,4]))

def mul(mul_list):
    mul1=1
    for a in mul_list:
        mul1 = mul1*a
    return mul1
print(mul([1,2,3,4,5]))

7、Define a function reverse() that computes the reversal of a string. For example, reverse("I am testing") should return the string "gnitset ma I".
定义计算字符串反转的函数reverse（）。例如，Reverse（“I am testing”）应该返回字符串“gnitset ma i”。

def reverse(string):
    revStr = ''
    for i in range(len(string)):
        revStr += string[len(string) - i - 1]

    return revStra

print(reverse('test'))

#方法二

def reverse(string):
    revStr=''
    for i in range(len(string)-1, -1, -1):
        revStr += string[i]

    return revStr

print(reverse('test'))

8、Define a function is_palindrome() that recognizes palindromes (i.e. words that look the same written backwards). For example, is_palindrome("radar") should return True.
定义一个函数是识别回文的_palindrome（）（即向后写的单词）。例如，“回文”（“radar”）应该返回true。

def is_palindrome(string):
    if string == ''.join(list(reversed(string))):#reversed输出的是一个迭代器
        return True
    else:
        return False
print(is_palindrome('8radar8'))

#迭代器：http://www.runoob.com/python3/python3-iterator-generator.html
#Python join() 方法用于将序列中的元素以指定的字符连接生成一个新的字符串。
#.join: http://www.runoob.com/python3/python3-string-join.html

9、Write a function is_member() that takes a value (i.e. a number, string, etc) 
x and a list of values a, and returns True if x is a member of a, False otherwise. (Note that this is exactly 
what the in operator does, but for the sake of the exercise you should pretend Python did not have this operator.)

写一个函数是获取一个值（即数字、字符串等）的_member（）。

x和值a的列表，如果x是a的成员，则返回true，否则返回false。（注意，这正是

in操作符所做的，但是为了练习，您应该假装python没有这个操作符。）

def is_member(x,a_list):
    for b in a_list:
        if x==b:
            return True
    return False

print(is_member(3,[2,3,4]))

10、Define a function overlapping() that takes two lists and returns True if they have at least one member in common, False otherwise. You may use your is_member() function, or the in operator, but for the sake of the exercise, you should (also) write it using two nested for-loops.

定义一个函数overlapping（），该函数接受两个列表，如果它们至少有一个公共成员，则返回true，否则返回false。您可以使用is_member（）函数或in运算符，但为了练习，您还应该（也）使用两个嵌套的for循环来编写它。

def overlapping(list1,list2):
    for a in list1:
        for b in list2:
            if a==b:
                return True
    return False
print(overlapping([1,2,3],[11,5,6,7]))

11.Define a function generate_n_chars() that takes an integer n and a character c and returns a string, n characters long, consisting only of c:s. 
For example, generate_n_chars(5,"x") should return the string "xxxxx". (Python is unusual in that you can actually write an expression 5 * "x" 
that will evaluate to "xxxxx". For the sake of the exercise you should ignore that the problem can be solved in this manner.)

def generate_n_chars(n,c):
    list1=[]
    for i in range(n):
        list1.append(c)#注意append的用法，之前写成了list1=list1.append()  这样就错了
    return ''.join(list1)
print(generate_n_chars(10,'s2'))

12、Define a procedure histogram() that takes a list of integers and prints a histogram to the screen. 
For example, histogram([4, 9, 7]) should print the following:

****

*********

*******

def histogram(list1):
    list2=[]
    for a in list1:
        list2.append(a*'*')
    return '\n'.join(list2)

print(histogram([3,4,5]))