python程序编写

#3
with open(r"E:\1.txt",'r') as f:
    f1 = f.read().swapcase()
    print(f1)
with open(r"E:\1.txt", 'w') as f:
    f.write(f1)

#4
def process_file(dst):     # 读文件到缓冲区
    try:     # 打开文件
        f = open(dst, 'r')
    except IOError as s:
        print(s)
        return None
    try:     # 读文件到缓冲区
        bvffer = f.read()
    except:
        print("Read File Error!")
        return None
    f.close()
    return bvffer

def process_buffer(bvffer):
    if bvffer:
        word_freq = {}
        # 下面添加处理缓冲区 bvffer代码，统计每个单词的频率，存放在字典word_freq
        bvffer = bvffer.lower()
        for ch in '“‘!;,.?”':
            bvffer = bvffer.lower().replace(ch, " ")  #将所有字母转换成小写，便于统计
        words = bvffer.strip().split()         #strip消除空白符，split以空格作为单词分界
        for word in words:
            word_freq[word] = word_freq.get(word, 0)+1  #读取到的单词存放到字典
        return word_freq
def output_result(word_freq):
    if word_freq:
        sorted_word_freq = sorted(word_freq.items(), key=lambda v: v[1], reverse=True)
        for item in sorted_word_freq[:10]:  # 输出 Top 10 的单词
            print (item[0], item[1],)
if __name__ == "__main__":
    dst = r"E:\2.txt"
    bvffer = process_file(dst)
    word_freq = process_buffer(bvffer)
    output_result(word_freq)