统计以a和b字母开头的单词的个数。 在task1.txt存放的是很多单词,请统计以a开头和以b开头出现的单词个数。
时间: 2024-03-22 11:42:46 浏览: 13
好的,我可以帮你编写一个Python程序来解决这个问题。你可以按照以下步骤操作:
1. 打开 `task1.txt` 文件,并读取其中的内容。
2. 将文件中的所有单词存储到一个列表中。
3. 遍历列表,统计以 a 和 b 开头的单词个数。
4. 输出统计结果。
以下是Python代码实现:
```python
a_count = 0
b_count = 0
with open('task1.txt', 'r') as f:
words = f.read().split()
for word in words:
if word.startswith('a') or word.startswith('A'):
a_count += 1
elif word.startswith('b') or word.startswith('B'):
b_count += 1
print('以a开头的单词个数:', a_count)
print('以b开头的单词个数:', b_count)
```
注意:代码中的 `task1.txt` 文件需要与代码文件放在同一个目录下,否则需要提供文件的完整路径。
相关问题
hadoop统计以a和b字母开头的单词的个数
你可以使用Hadoop的MapReduce编程模型来实现统计以a和b字母开头的单词的个数。以下是一个可能的实现步骤:
1. 编写一个Mapper类,将输入的文本文件拆分成单词,并标记以a或b字母开头的单词。
2. 编写一个Reducer类,对标记过的单词进行计数。
3. 配置Hadoop作业的输入和输出路径,并指定Mapper和Reducer类。
4. 运行Hadoop作业并等待结果。
以下是一个可能的Mapper和Reducer实现示例:
```java
public class ABWordsMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String line = value.toString();
StringTokenizer tokenizer = new StringTokenizer(line);
while (tokenizer.hasMoreTokens()) {
String token = tokenizer.nextToken();
if (token.startsWith("a") || token.startsWith("b")) {
word.set(token);
context.write(word, one);
}
}
}
}
public class ABWordsReducer extends Reducer<Text, IntWritable, Text, IntWritable> {
private IntWritable result = new IntWritable();
public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
result.set(sum);
context.write(key, result);
}
}
```
配置Hadoop作业的输入和输出路径:
```java
Job job = Job.getInstance(conf, "AB word count");
job.setJarByClass(ABWordCount.class);
job.setMapperClass(ABWordsMapper.class);
job.setCombinerClass(ABWordsReducer.class);
job.setReducerClass(ABWordsReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
```
运行Hadoop作业:
```java
System.exit(job.waitForCompletion(true) ? 0 : 1);
```
注意:以上代码示例仅供参考,实际实现可能需要根据具体情况进行修改。
hadoop统计以a和b字母开头的单词的个数代码
下面是一个简单的Hadoop MapReduce代码,用于统计以a和b字母开头的单词的个数:
Mapper类:
```
public class ABWordCountMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
private final static IntWritable one = new IntWritable(1);
private Text word = new Text();
@Override
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
String line = value.toString();
StringTokenizer tokenizer = new StringTokenizer(line);
while (tokenizer.hasMoreTokens()) {
String nextToken = tokenizer.nextToken();
if (nextToken.startsWith("a") || nextToken.startsWith("b")) {
word.set(nextToken);
context.write(word, one);
}
}
}
}
```
Reducer类:
```
public class ABWordCountReducer extends Reducer<Text, IntWritable, Text, IntWritable> {
private IntWritable result = new IntWritable();
@Override
public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
int sum = 0;
for (IntWritable val : values) {
sum += val.get();
}
result.set(sum);
context.write(key, result);
}
}
```
Driver类:
```
public class ABWordCountDriver {
public static void main(String[] args) throws Exception {
Configuration conf = new Configuration();
Job job = Job.getInstance(conf, "AB word count");
job.setJarByClass(ABWordCountDriver.class);
job.setMapperClass(ABWordCountMapper.class);
job.setCombinerClass(ABWordCountReducer.class);
job.setReducerClass(ABWordCountReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}
```
在运行MapReduce作业之前,请确保已经安装并配置好了Hadoop,并且已经将输入文件上传到HDFS中。使用以下命令来提交MapReduce作业:
```
hadoop jar ABWordCount.jar ABWordCountDriver input output
```
其中,ABWordCount.jar是包含所有类文件的JAR文件,input是输入文件的路径,output是输出文件的路径。
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