python 学习 1

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定义函数计算传入参数中数字的个数

def count_digits(n):
    """Counts the number of digits in the given number.
    
        >>> count_digits(5)
        1
        >>> count_digits(42)
        2
        >>> count_digits(9876543210)
        10
        >>> count_digits(2 ** 100)
        31
    """
    # your code here
    tempstr=str(n)
    count=0
    for i in range(0,len(tempstr)):
        if tempstr[i]<='9' and tempstr[i]>='0':
            global count
            count=count+1
            
    return count

在首次写法中，丢失global count 使的函数内部count=count+1 出现语法错误