写一个包，里面实现一个模块'模块里面有个类，有两个实例方法，一个方法可以统计有个路径文件的英文个数，一个是统计空白字符个数

实现方法：

新建一个目录：count

下面新建一个文件 __init__.py

class Count(object):

    def __init__(self,file_path):

        self.file_path = file_path

    def count_letter_num(self):

        letter_num = 0

        try:

            with open(self.file_path) as fp:

                for line in fp:

                    for letter in line:

                        if (letter >="a" and letter<="z") or \

                        (letter >="A" and letter<="Z"):

                            letter_num +=1

            return letter_num

        except IOError as e:

            print(e)

            return None

    def count_space_num(self):

        space_num = 0

        try:

            with open(self.file_path) as fp:

                for line in fp:

                    for letter in line:

                        if letter.isspace():

                            space_num +=1

            return space_num

        except IOError as e:

            print(e)

            return None

#调用的程序：

import count.string_count

f = count.string_count.Count("e:\\b.py")

print(f.count_letter_num())

print(f.count_space_num())