[英]Sum of digits in a string
if i just read my sum_digits
function here, it makes sense in my head but it seems to be producing wrong results.如果我只是在这里阅读我的sum_digits
函数,它在我的脑海中是有道理的,但它似乎产生了错误的结果。 Any tip?任何提示?
def is_a_digit(s):
''' (str) -> bool
Precondition: len(s) == 1
Return True iff s is a string containing a single digit character (between
'0' and '9' inclusive).
>>> is_a_digit('7')
True
>>> is_a_digit('b')
False
'''
return '0' <= s and s <= '9'
def sum_digits(digit):
b = 0
for a in digit:
if is_a_digit(a) == True:
b = int(a)
b += 1
return b
For the function sum_digits
, if i input sum_digits('hihello153john')
, it should produce 9
对于函数sum_digits
,如果我输入sum_digits('hihello153john')
,它应该产生9
Notice that you can easily solve this problem using built-in functions. 请注意,您可以使用内置函数轻松解决此问题。 This is a more idiomatic and efficient solution: 这是一个更加惯用和有效的解决方案:
def sum_digits(digit):
return sum(int(x) for x in digit if x.isdigit())
sum_digits('hihello153john')
=> 9
In particular, be aware that the is_a_digit()
method already exists for string types, it's called isdigit()
. 特别要注意,对于字符串类型, is_a_digit()
方法已经存在,它称为isdigit()
。
And the whole loop in the sum_digits()
function can be expressed more concisely using a generator expression as a parameter for the sum()
built-in function, as shown above. 如上所示,使用生成器表达式作为内置函数sum()
的参数,可以更简洁地表示sum_digits()
函数中的整个循环。
You're resetting the value of b
on each iteration, if a
is a digit. 如果a
是数字,则每次迭代时都要重置b
的值。
Perhaps you want: 也许您想要:
b += int(a)
Instead of: 代替:
b = int(a)
b += 1
一支班轮
sum_digits = lambda x: sum(int(y) for y in x if y.isdigit())
I would like to propose a different solution using regx that covers two scenarios: 我想提出一个使用regx的不同解决方案,该方案涵盖两种情况:
1. 1。
Input = 'abcd45def05' 输入='abcd45def05'
Output = 45 + 05 = 50 输出= 45 + 05 = 50
import re
print(sum(int(x) for x in re.findall(r'[0-9]+', my_str)))
Notice the '+' for one or more occurrences 注意一个或多个事件的“ +”号
2. 2。
Input = 'abcd45def05' 输入='abcd45def05'
Output = 4 + 5 + 0 + 5 = 14 输出= 4 + 5 + 0 + 5 = 14
import re
print(sum(int(x) for x in re.findall(r'[0-9]', my_str)))
Another way of doing it: 另一种方法是:
def digit_sum(n):
new_n = str(n)
sum = 0
for i in new_n:
sum += int(i)
return sum
An equivalent for your code, using list comprehensions: 使用列表推导等效于您的代码:
def sum_digits(your_string):
return sum(int(x) for x in your_string if '0' <= x <= '9')
It will run faster then a "for" version, and saves a lot of code. 它比“ for”版本运行得更快,并节省了大量代码。
Just a variation to @oscar's answer, if we need the sum to be single digit, 只是@oscar答案的一种变体,如果我们需要总和为一位数,
def sum_digits(digit):
s = sum(int(x) for x in str(digit) if x.isdigit())
if len(str(s)) > 1:
return sum_digits(s)
else:
return s
#if string =he15ll15oo10
#sum of number =15+15+10=40
def sum_of_all_Number(s):
num = 0
sum = 0
for i in s:
if i.isdigit():
num = num * 10 + int(i)
else:
sum = sum + num
num = 0
return sum+num
#if string =he15ll15oo10
#sum of digit=1+5+1+5+1+0=13
def sum_of_Digit(s):
sum = 0
for i in s:
if i.isdigit():
sum= sum + int(i)
return sum
s = input("Enter any String ")
print("Sum of Number =", sum_of_all_Number(s))
print("Sum Of Digit =", sum_of_Digit(s))
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