import pandas as pd import matplotlib import numpy as np import matplotlib.pyplot as plt import jieba as jb import re from sklearn.feature_extraction.text import TfidfVectorizer from sklearn.feature_selection import chi2 import numpy as np from sklearn.model_selection import train_test_split from sklearn.feature_extraction.text import CountVectorizer from sklearn.feature_extraction.text import TfidfTransformer from sklearn.naive_bayes import MultinomialNB def sigmoid(x): return 1 / (1 + np.exp(-x)) import numpy as np #定义删除除字母,数字,汉字以外的所有符号的函数 def remove_punctuation(line): line = str(line) if line.strip()=='': return '' rule = re.compile(u"[^a-zA-Z0-9\u4E00-\u9FA5]") line = rule.sub('',line) return line def stopwordslist(filepath): stopwords = [line.strip() for line in open(filepath, 'r', encoding='utf-8').readlines()] return stopwords df = pd.read_csv('./online_shopping_10_cats/online_shopping_10_cats.csv') df=df[['cat','review']] df = df[pd.notnull(df['review'])] d = {'cat':df['cat'].value_counts().index, 'count': df['cat'].value_counts()} df_cat = pd.DataFrame(data=d).reset_index(drop=True) df['cat_id'] = df['cat'].factorize()[0] cat_id_df = df[['cat', 'cat_id']].drop_duplicates().sort_values('cat_id').reset_index(drop=True) cat_to_id = dict(cat_id_df.values) id_to_cat = dict(cat_id_df[['cat_id', 'cat']].values) #加载停用词 stopwords = stopwordslist("./online_shopping_10_cats/chineseStopWords.txt") #删除除字母,数字,汉字以外的所有符号 df['clean_review'] = df['review'].apply(remove_punctuation) #分词,并过滤停用词 df['cut_review'] = df['clean_review'].apply(lambda x: " ".join([w for w in list(jb.cut(x)) if w not in stopwords])) tfidf = TfidfVectorizer(norm='l2', ngram_range=(1, 2)) features = tfidf.fit_transform(df.cut_review) labels = df.cat_id X_train, X_test, y_train, y_test = train_test_split(df['cut_review'], df['cat_id'], random_state = 0) count_vect = CountVectorizer() X_train_counts = count_vect.fit_transform(X_train) tfidf_transformer = TfidfTransformer() X_train_tfidf = tfidf_transformer.fit_transform(X_train_counts) 已经写好以上代码,请补全train和test函数
时间: 2024-02-25 21:54:59 浏览: 26
以下是train和test函数的代码:
```python
def train(X_train_tfidf, y_train):
clf = MultinomialNB().fit(X_train_tfidf, y_train)
return clf
def test(clf, X_test):
X_test_counts = count_vect.transform(X_test)
X_test_tfidf = tfidf_transformer.transform(X_test_counts)
y_pred = clf.predict(X_test_tfidf)
return y_pred
```
train函数使用MultinomialNB()方法来拟合特征矩阵和标签,返回训练后的分类器clf。
test函数使用训练好的分类器clf来预测X_test的标签,返回预测结果y_pred。在预测之前,需要使用之前定义的count_vect和tfidf_transformer对X_test进行向量化和tf-idf转换。
相关问题
import pandas as pd import numpy as np import matplotlib.pyplot as plt import seaborn as sns from sklearn import tree
以下是使用import语句导入pandas、numpy、matplotlib.pyplot、seaborn和sklearn.tree的示例代码:
```python
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
from sklearn import tree
```
- pandas是一个数据处理库,用于读取、处理和分析数据。
- numpy是一个数学库,用于处理数组和矩阵等数学运算。
- matplotlib.pyplot是一个绘图库,用于绘制各种类型的图表。
- seaborn是一个基于matplotlib的数据可视化库,提供了更高级别的界面和更多的图表类型。
- sklearn.tree是scikit-learn库中的一个模块,用于实现决策树算法。
import numpy as np import pandas as pd import matplotlib.pyplot as plt
这三个库都是Python中常用的数据分析和可视化库。其中,NumPy是Python中用于科学计算的基础库,提供了高性能的多维数组和矩阵计算功能。Pandas是基于NumPy的一个数据处理库,提供了高效的数据结构和数据分析工具。Matplotlib是Python中最流行的数据可视化库之一,提供了各种绘图工具和图表类型,可以用于生成各种静态和动态的图表。
以下是一个简单的例子,展示如何使用这三个库绘制一个柱状图:
```python
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
# 创建数据
bar_positions = [1, 2, 3, 4]
bar_heights = [1, 2, 3, 4]
# 绘制柱状图
fig, ax = plt.subplots()
ax.bar(np.arange(len(bar_positions)), bar_heights)
# 设置x轴标签
ax.set_xticks(np.arange(len(bar_positions)))
ax.set_xticklabels(bar_positions)
# 设置y轴标签
ax.set_ylabel('Bar Heights')
# 设置图表标题
ax.set_title('A Simple Bar Chart')
# 显示图表
plt.show()
```