def test_tf_applier_pandas_generator(self):
df = self._get_x_df_with_str()
policy = RandomPolicy(1,
sequence_length=2,
n_per_original=2,
keep_original=False)
applier = PandasTFApplier([square], policy)
gen = applier.apply_generator(df, batch_size=2)
df_expected = [
pd.DataFrame(
{
"num": [1, 1, 16, 16],
"strs": ["x", "x", "y", "y"]
},
index=[0, 0, 1, 1],
),
pd.DataFrame({
"num": [81, 81],
"strs": ["z", "z"]
}, index=[2, 2]),
]
for df_batch, df_batch_expected in zip(gen, df_expected):
self.assertEqual(df_batch.num.dtype, "int64")
pd.testing.assert_frame_equal(df_batch, df_batch_expected)
pd.testing.assert_frame_equal(df, self._get_x_df_with_str())
def main():
df = pd.read_csv('../airbnb/reviews.tsv', sep='\t')
newdf = df[['comments', 'Great (1) Not Great (0)']]
newdf.columns = ['text', 'label']
chunks = []
labels = []
buffer = []
for i, row in newdf.iterrows():
sents = nltk.sent_tokenize(row['text'])
for sent in sents:
buffer.append(sent)
if (len(buffer)) % 3 == 0:
chunks.append(" ".join(buffer))
labels.append(row['label'])
buffer = [buffer[random.randint(0, 2)]]
if len(buffer) > 1:
chunks.append(" ".join(buffer))
labels.append(row['label'])
buffer = []
chunkedDf = pd.DataFrame({'text': chunks, 'label': labels})
random_policy = RandomPolicy(len(tfs),
sequence_length=4,
n_per_original=1,
keep_original=True)
tf_applier = PandasTFApplier(tfs, random_policy)
newdf_augmented = tf_applier.apply(chunkedDf)
print(len(newdf))
print(len(newdf_augmented))
newdf_augmented.to_csv('airbnb_augmented.csv')
def test_tf_applier_pandas_modify_in_place(self):
df = self._get_x_df_dict()
policy = ApplyOnePolicy(n_per_original=2, keep_original=True)
applier = PandasTFApplier([modify_in_place], policy)
df_augmented = applier.apply(df, progress_bar=False)
idx = [0, 0, 0, 1, 1, 1, 2, 2, 2]
df_expected = pd.DataFrame(
dict(d=get_data_dict(DATA_IN_PLACE_EXPECTED)), index=idx)
pd.testing.assert_frame_equal(df_augmented, df_expected)
pd.testing.assert_frame_equal(df, self._get_x_df_dict())
def test_tf_applier_returns_none(self):
df = self._get_x_df()
policy = RandomPolicy(1,
sequence_length=2,
n_per_original=2,
keep_original=True)
applier = PandasTFApplier([square_returns_none], policy)
df_augmented = applier.apply(df, progress_bar=False)
df_expected = pd.DataFrame(dict(num=[1, 1, 1, 2, 3, 81, 81]),
index=[0, 0, 0, 1, 2, 2, 2])
self.assertEqual(df_augmented.num.dtype, "int64")
pd.testing.assert_frame_equal(df_augmented, df_expected)
pd.testing.assert_frame_equal(df, self._get_x_df())
def test_tf_applier_pandas_modify_in_place_generator(self):
df = self._get_x_df_dict()
policy = ApplyOnePolicy(n_per_original=2, keep_original=True)
applier = PandasTFApplier([modify_in_place], policy)
gen = applier.apply_generator(df, batch_size=2)
idx = [0, 0, 0, 1, 1, 1, 2, 2, 2]
df_expected = [
make_df(get_data_dict(DATA_IN_PLACE_EXPECTED[:6]), idx[:6], key="d"),
make_df(get_data_dict(DATA_IN_PLACE_EXPECTED[6:]), idx[6:], key="d"),
]
for df_batch, df_batch_expected in zip(gen, df_expected):
pd.testing.assert_frame_equal(df_batch, df_batch_expected)
pd.testing.assert_frame_equal(df, self._get_x_df_dict())
def test_tf_applier_returns_none_generator(self):
df = self._get_x_df()
policy = RandomPolicy(
1, sequence_length=2, n_per_original=2, keep_original=True
)
applier = PandasTFApplier([square_returns_none], policy)
gen = applier.apply_generator(df, batch_size=2)
df_expected = [
make_df([1, 1, 1, 2], [0, 0, 0, 1]),
make_df([3, 81, 81], [2, 2, 2]),
]
for df_batch, df_batch_expected in zip(gen, df_expected):
pd.testing.assert_frame_equal(df_batch, df_batch_expected)
pd.testing.assert_frame_equal(df, self._get_x_df())
def apply_tf_on_data(df_train):
"""
Here we apply the transformation functions (from transformation_function.py)
on the given train data frame.
Return the enlarged data frame.
"""
print("")
print("Transformation Functions:")
tfs = [transformation_function.change_perek, transformation_function.change_masechet]
random_policy = RandomPolicy(
len(tfs), sequence_length=len(tfs), n_per_original=TRANSFORMATION_FACTOR, keep_original=True
)
print("-Applying ["+str(len(tfs))+"] transformation functions with factor ["+str(TRANSFORMATION_FACTOR)+"] ...")
tf_applier = PandasTFApplier(tfs, random_policy)
df_train_augmented = tf_applier.apply(df_train)
# Y_train_augmented = df_train_augmented["tag"].values
print("DONE")
return df_train_augmented
def test_tf_applier_pandas(self):
df = self._get_x_df_with_str()
policy = RandomPolicy(1,
sequence_length=2,
n_per_original=1,
keep_original=False)
applier = PandasTFApplier([square], policy)
df_augmented = applier.apply(df, progress_bar=False)
df_expected = pd.DataFrame(dict(num=[1, 16, 81], strs=STR_DATA),
index=[0, 1, 2])
self.assertEqual(df_augmented.num.dtype, "int64")
pd.testing.assert_frame_equal(df_augmented, df_expected)
pd.testing.assert_frame_equal(df, self._get_x_df_with_str())
df_augmented = applier.apply(df, progress_bar=True)
df_expected = pd.DataFrame(dict(num=[1, 16, 81], strs=STR_DATA),
index=[0, 1, 2])
pd.testing.assert_frame_equal(df_augmented, df_expected)
pd.testing.assert_frame_equal(df, self._get_x_df_with_str())
def augmentation_evaluation(df_train, df_test, policy, p=None):
tfs = [
TransformationFunction.change_addr,
TransformationFunction.change_business,
TransformationFunction.change_o,
TransformationFunction.randomly_delete,
TransformationFunction.randomly_add
]
if policy == "random":
random_policy = RandomPolicy(len(tfs),
sequence_length=2,
n_per_original=2,
keep_original=True)
tf_applier = PandasTFApplier(tfs, random_policy)
df_train_augmented = tf_applier.apply(df_train)
Y_train_augmented = df_train_augmented["label"].values
print(f"Original training set size: {len(df_train)}")
print(f"Augmented training set size: {len(df_train_augmented)}")
return df_train_augmented, Y_train_augmented
if policy == "mean":
if p is None:
p = [0.1, 0.1, 0.1, 0.35, 0.35]
mean_field_policy = MeanFieldPolicy(
len(tfs),
sequence_length=
2, # how many TFs to apply uniformly at random per data point
n_per_original=
2, # how many augmented data points to generate per original data point
keep_original=True,
p=p, # specify a sampling distribution for the TFs
)
tf_applier = PandasTFApplier(tfs, mean_field_policy)
df_train_augmented = tf_applier.apply(df_train)
Y_train_augmented = df_train_augmented["label"].values
print(f"Original training set size: {len(df_train)}")
print(f"Augmented training set size: {len(df_train_augmented)}")
return df_train_augmented, Y_train_augmented
words = x.text.lower().split()
idx = random.choice(range(len(words)))
synonyms = get_synonyms(words[idx])
if len(synonyms) > 0:
x.text = " ".join(words[:idx] + [synonyms[0]] + words[idx + 1:])
return x
# %% [markdown]
# Next, we apply this transformation function to our training dataset:
# %%
from snorkel.augmentation import ApplyOnePolicy, PandasTFApplier
tf_policy = ApplyOnePolicy(n_per_original=2, keep_original=True)
tf_applier = PandasTFApplier([tf_replace_word_with_synonym], tf_policy)
df_train_augmented = tf_applier.apply(df_train)
# %% [markdown]
# Note that a common challenge with data augmentation is figuring out how to tune and apply different transformation functions to best augment a training set.
# This is most commonly done as an ad hoc manual process; however, in Snorkel, various approaches for using automatically learned data augmentation _policies_ are supported.
# For more detail, see the [Spam TFs tutorial](https://snorkel.org/use-cases/02-spam-data-augmentation-tutorial).
# %% [markdown]
# ## 4) Writing a Slicing Function
#
# Finally, a third operator in Snorkel, *slicing functions (SFs)*, handles the reality that many datasets have certain subsets or _slices_ that are more important than others.
# In Snorkel, we can write SFs to (a) monitor specific slices and (b) improve model performance over them by adding representational capacity targeted on a per-slice basis.
#
# Writing a slicing function is simple.
# For example, we could write one that looks for suspiciously shortened links, which might be critical due to their likelihood of linking to malicious sites:
len(tfs),
sequence_length=2,
n_per_original=2,
keep_original=True,
p=[0.05, 0.05, 0.3, 0.3, 0.3],
)
# %% [markdown]
# To apply one or more TFs that we've written to a collection of data points according to our policy, we use a
# [`PandasTFApplier`](https://snorkel.readthedocs.io/en/master/packages/_autosummary/augmentation/snorkel.augmentation.PandasTFApplier.html)
# because our data points are represented with a Pandas DataFrame.
# %% {"tags": ["md-exclude-output"]}
from snorkel.augmentation import PandasTFApplier
tf_applier = PandasTFApplier(tfs, mean_field_policy)
df_train_augmented = tf_applier.apply(df_train)
Y_train_augmented = df_train_augmented["label"].values
# %%
print(f"Original training set size: {len(df_train)}")
print(f"Augmented training set size: {len(df_train_augmented)}")
# %% [markdown]
# We have almost doubled our dataset using TFs!
# Note that despite `n_per_original` being set to 2, our dataset may not exactly triple in size,
# because sometimes TFs return `None` instead of a new data point
# (e.g. `change_person` when applied to a sentence with no persons).
# If you prefer to have exact proportions for your dataset, you can have TFs that can't perform a
# valid transformation return the original data point rather than `None` (as they do here).
