Got continuous is not supported error in RandomForestRegressor

I’m just trying to do a simple RandomForestRegressor example. But while testing the accuracy I get this error

/Users/noppanit/anaconda/lib/python2.7/site-packages/sklearn/metrics/classification.pyc

in accuracy_score(y_true, y_pred, normalize, sample_weight)
177
178 # Compute accuracy for each possible representation
–> 179 y_type, y_true, y_pred = _check_targets(y_true, y_pred)
180 if y_type.startswith(‘multilabel’):
181 differing_labels = count_nonzero(y_true – y_pred, axis=1)

/Users/noppanit/anaconda/lib/python2.7/site-packages/sklearn/metrics/classification.pyc

in _check_targets(y_true, y_pred)
90 if (y_type not in [“binary”, “multiclass”, “multilabel-indicator”,
91 “multilabel-sequences”]):
—> 92 raise ValueError(“{0} is not supported”.format(y_type))
93
94 if y_type in [“binary”, “multiclass”]:

ValueError: continuous is not supported

This is the sample of the data. I can’t show the real data.

target, func_1, func_2, func_2, ... func_200
float, float, float, float, ... float

Here’s my code.

import pandas as pd
import numpy as np
from sklearn.preprocessing import Imputer
from sklearn.ensemble import RandomForestClassifier, RandomForestRegressor, ExtraTreesRegressor, GradientBoostingRegressor
from sklearn.cross_validation import train_test_split
from sklearn.metrics import accuracy_score
from sklearn import tree

train = pd.read_csv('data.txt', sep='t')

labels = train.target
train.drop('target', axis=1, inplace=True)
cat = ['cat']
train_cat = pd.get_dummies(train[cat])

train.drop(train[cat], axis=1, inplace=True)
train = np.hstack((train, train_cat))

imp = Imputer(missing_values='NaN', strategy='mean', axis=0)
imp.fit(train)
train = imp.transform(train)

x_train, x_test, y_train, y_test = train_test_split(train, labels.values, test_size = 0.2)

clf = RandomForestRegressor(n_estimators=10)

clf.fit(x_train, y_train)
y_pred = clf.predict(x_test)
accuracy_score(y_test, y_pred) # This is where I get the error.