Tag Archives: NLP

NLTK Error [nltk_data] Error loading stopwords: hostname

Nltk error [nltk]_ Data] error loading stopwords: host name. Use the following code to download stopwords

import nltk
import ssl

try:
    _create_unverified_https_context = ssl._create_unverified_context
except AttributeError:
    pass
else:
    ssl._create_default_https_context = _create_unverified_https_context
    

nltk.download('stopwords')
nltk.download('punkt')

Sklearn ValueError: empty vocabulary; perhaps the documents only contain stop words

Chinese corpus:

A list of words

I don’t have much inside glory
If Huawei users find that the battery life is less than one day, please use Mr. Yu’s microblog to protect their rights reasonably
it’s cheaper than 500 g

use

CountVectorizer()

report errors:

Sklearn ValueError: empty vocabulary; perhaps the documents only contain stop words

 

Question:

def __init__(self, input='content', encoding='utf-8',
             decode_error='strict', strip_accents=None,
             lowercase=True, preprocessor=None, tokenizer=None,
             stop_words=None, token_pattern=r"(?u)\b\w\w+\b",
             ngram_range=(1, 1), analyzer='word',
             max_df=1.0, min_df=1, max_features=None,
             vocabulary=None, binary=False, dtype=np.int64):

Solution

Countvectorizer () defaults to analysis = “word”, and changes to countvectorizer (analysis = “char”, lowercase = false)

 

 

download (‘point’) False

The following is the operation of using NLTK for word segmentation and then removing stop_words, but when it runs, it is prompted to download PUNkt.

from nltk.corpus import stopwords
from nltk.tokenize import word_tokenize

example_sent = "This is a sample sentence, showing off the stop words filtration."

stop_words = set(stopwords.words('english'))

word_tokens = word_tokenize(example_sent)

filtered_sentence = [w for w in word_tokens if not w in stop_words]

filtered_sentence = []

for w in word_tokens:
    if w not in stop_words:
        filtered_sentence.append(w)

print(word_tokens)
print(filtered_sentence)

Our output here:



['This', 'is', 'a', 'sample', 'sentence', ',', 'showing', 'off', 'the', 'stop', 'words', 'filtration', '.']
['This', 'sample', 'sentence', ',', 'showing', 'stop', 'words', 'filtration', '.']

After several attempts, it turned out to be False.

changed other people’s machine, it’s good…
I want to copy the directory to the failed directory on my machine:

Solve runtimeerror: reduce failed to synchronize: device side assert triggered problem

first, the previous wave reported an error message:

/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [96,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [97,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [98,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [99,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [100,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [101,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [102,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [103,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, 
......
......
......
/pytorch/aten/src/THC/THCTensorIndex.cu:362: void indexSelectLargeIndex(TensorInfo<T, IndexType>, TensorInfo<T, IndexType>, TensorInfo<long, IndexType>, int, int, IndexType, IndexType, long) [with T = float, IndexType = unsigned int, DstDim = 2, SrcDim = 2, IdxDim = -2, IndexIsMajor = true]: block: [35,0,0], thread: [95,0,0] Assertion `srcIndex < srcSelectDimSize` failed.
Traceback (most recent call last):
  File "../paragrah_selector/para_sigmoid_train.py", line 533, in <module>
    main()
  File "../paragrah_selector/para_sigmoid_train.py", line 463, in main
    eval_loss = eval_model(model, eval_data, device)
  File "../paragrah_selector/para_sigmoid_train.py", line 419, in eval_model
    loss, logits = model(input_ids, segment_ids, input_mask, labels=label_ids)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/parallel/data_parallel.py", line 143, in forward
    outputs = self.parallel_apply(replicas, inputs, kwargs)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/parallel/data_parallel.py", line 153, in parallel_apply
    return parallel_apply(replicas, inputs, kwargs, self.device_ids[:len(replicas)])
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/parallel/parallel_apply.py", line 83, in parallel_apply
    raise output
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/parallel/parallel_apply.py", line 59, in _worker
    output = module(*input, **kwargs)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/caiyun_projects/generative_mrc/paragrah_selector/modeling.py", line 1001, in forward
    loss = loss_fn(logits, labels)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/loss.py", line 504, in forward
    return F.binary_cross_entropy(input, target, weight=self.weight, reduction=self.reduction)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/functional.py", line 2027, in binary_cross_entropy
    input, target, weight, reduction_enum)
RuntimeError: reduce failed to synchronize: device-side assert triggered
terminate called after throwing an instance of 'c10::Error'
  what():  CUDA error: device-side assert triggered (insert_events at /pytorch/aten/src/THC/THCCachingAllocator.cpp:470)
frame #0: std::function<std::string ()>::operator()() const + 0x11 (0x7f0e52afc021 in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libc10.so)
frame #1: c10::Error::Error(c10::SourceLocation, std::string const&) + 0x2a (0x7f0e52afb8ea in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libc10.so)
frame #2: <unknown function> + 0x13dbd92 (0x7f0e5e065d92 in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libcaffe2_gpu.so)
frame #3: at::TensorImpl::release_resources() + 0x50 (0x7f0e534c6440 in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libcaffe2.so)
frame #4: <unknown function> + 0x2af03b (0x7f0e51bb703b in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libtorch.so.1)
frame #5: torch::autograd::Variable::Impl::release_resources() + 0x17 (0x7f0e51e29d27 in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libtorch.so.1)
frame #6: <unknown function> + 0x124cfb (0x7f0e8ce4ccfb in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libtorch_python.so)
frame #7: <unknown function> + 0x3204af (0x7f0e8d0484af in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libtorch_python.so)
frame #8: <unknown function> + 0x3204f1 (0x7f0e8d0484f1 in /home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/lib/libtorch_python.so)
<omitting python frames>
frame #25: __libc_start_main + 0xf0 (0x7f0ecf782830 in /lib/x86_64-linux-gnu/libc.so.6)

Aborted (core dumped)
(py36) [email protected]:~/caiyun_projects/generative_mrc/script$ sh para_sigmoid_train.sh

before heading off to New York next week, we appear under the heading of
before heading off to New York next week. We haven’t lost our labels before heading off to New York before heading off to New York next week. We haven’t lost our labels before heading off to New York next week. And so on. So check your labels carefully. 2. There is something wrong with your word vector, such as the position vector exceeding the preset length of the model, the word vector exceeding the size of the word table, etc.

And then, the point of this article, if you just say these two reasons, it might not be easy to figure out the problem. Let me show you a simple debug method, and you’ll see what the problem is. That is: put the model on the CPU and run . If it doesn’t fit, just turn down the batch size. For example, after I finished the adjustment, I reported the following error:

File "../paragrah_selector/para_sigmoid_train.py", line 533, in <module>
    main()
  File "../paragrah_selector/para_sigmoid_train.py", line 463, in main
    eval_loss = eval_model(model, eval_data, device)
  File "../paragrah_selector/para_sigmoid_train.py", line 419, in eval_model
    loss, logits = model(input_ids, segment_ids, input_mask, labels=label_ids)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/caiyun_projects/generative_mrc/paragrah_selector/modeling.py", line 987, in forward
    _, pooled_output = self.bert(input_ids, token_type_ids, attention_mask, output_all_encoded_layers=False)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/caiyun_projects/generative_mrc/paragrah_selector/modeling.py", line 705, in forward
    embedding_output = self.embeddings(input_ids, token_type_ids)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/caiyun_projects/generative_mrc/paragrah_selector/modeling.py", line 281, in forward
    position_embeddings = self.position_embeddings(position_ids)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/module.py", line 489, in __call__
    result = self.forward(*input, **kwargs)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/modules/sparse.py", line 118, in forward
    self.norm_type, self.scale_grad_by_freq, self.sparse)
  File "/home/lisen/.conda/envs/py36/lib/python3.6/site-packages/torch/nn/functional.py", line 1454, in embedding
    return torch.embedding(weight, input, padding_idx, scale_grad_by_freq, sparse)
RuntimeError: index out of range at /pytorch/aten/src/TH/generic/THTensorEvenMoreMath.cpp:191

thorough analysis clearly shows that File “/home/lisen/caiyun_projects/generative_mrc/paragrah_selector/modeling. Py”, line 281, in forward
position_embeddings = self. Position_embeddings (position_ids) “, If the position vector exceeds the preset length value of the model, then I go back to check and find that the longer text is indeed not truncated to that length, leading to this problem.

Solution to unbalanced load of multiple cards (GPU’s 0 card is too high) in Python model training (simple and effective)

this paper mainly solves the problem that zero card of pytorch GPU occupies more video memory than other CARDS during model training. As shown in the figure below: the native GPU card is TITAN RTX, video memory is 24220M, batch_size = 9, and three CARDS are used. The 0th card video memory occupies 24207M. At this time, it just starts to run, and only a small amount of data is transferred to the video card. If the data is in multiple points, the video memory of the 0 card must burst. The reason why 0 card has higher video memory: During the back propagation of the network, the calculated gradient of loss is calculated on 0 card by default. So will be more than other graphics card some video memory, how much more specific, mainly to see the structure of the network.

as a result, in order to prevent training was interrupted due to out of memory. The foolhardy option is to set batch_size to 6, or 2 pieces of data per card.
batch_size = 6, the other the same, as shown in the figure below

have found the problem?Video memory USES only 1,2 CARDS and less than 16 gigabytes of memory. The batch_size is sacrificed because the 0 card might exceed a little bit of video memory.
so there’s no more elegant way?The answer is yes. That is borrowed from the transformer – xl BalancedDataParallel used in the class. The code is as follows (source) :

import torch
from torch.nn.parallel.data_parallel import DataParallel
from torch.nn.parallel.parallel_apply import parallel_apply
from torch.nn.parallel._functions import Scatter


def scatter(inputs, target_gpus, chunk_sizes, dim=0):
    r"""
    Slices tensors into approximately equal chunks and
    distributes them across given GPUs. Duplicates
    references to objects that are not tensors.
    """

    def scatter_map(obj):
        if isinstance(obj, torch.Tensor):
            try:
                return Scatter.apply(target_gpus, chunk_sizes, dim, obj)
            except Exception:
                print('obj', obj.size())
                print('dim', dim)
                print('chunk_sizes', chunk_sizes)
                quit()
        if isinstance(obj, tuple) and len(obj) > 0:
            return list(zip(*map(scatter_map, obj)))
        if isinstance(obj, list) and len(obj) > 0:
            return list(map(list, zip(*map(scatter_map, obj))))
        if isinstance(obj, dict) and len(obj) > 0:
            return list(map(type(obj), zip(*map(scatter_map, obj.items()))))
        return [obj for targets in target_gpus]

    # After scatter_map is called, a scatter_map cell will exist. This cell
    # has a reference to the actual function scatter_map, which has references
    # to a closure that has a reference to the scatter_map cell (because the
    # fn is recursive). To avoid this reference cycle, we set the function to
    # None, clearing the cell
    try:
        return scatter_map(inputs)
    finally:
        scatter_map = None


def scatter_kwargs(inputs, kwargs, target_gpus, chunk_sizes, dim=0):
    """Scatter with support for kwargs dictionary"""
    inputs = scatter(inputs, target_gpus, chunk_sizes, dim) if inputs else []
    kwargs = scatter(kwargs, target_gpus, chunk_sizes, dim) if kwargs else []
    if len(inputs) < len(kwargs):
        inputs.extend([() for _ in range(len(kwargs) - len(inputs))])
    elif len(kwargs) < len(inputs):
        kwargs.extend([{} for _ in range(len(inputs) - len(kwargs))])
    inputs = tuple(inputs)
    kwargs = tuple(kwargs)
    return inputs, kwargs


class BalancedDataParallel(DataParallel):

    def __init__(self, gpu0_bsz, *args, **kwargs):
        self.gpu0_bsz = gpu0_bsz
        super().__init__(*args, **kwargs)

    def forward(self, *inputs, **kwargs):
        if not self.device_ids:
            return self.module(*inputs, **kwargs)
        if self.gpu0_bsz == 0:
            device_ids = self.device_ids[1:]
        else:
            device_ids = self.device_ids
        inputs, kwargs = self.scatter(inputs, kwargs, device_ids)
        if len(self.device_ids) == 1:
            return self.module(*inputs[0], **kwargs[0])
        replicas = self.replicate(self.module, self.device_ids)
        if self.gpu0_bsz == 0:
            replicas = replicas[1:]
        outputs = self.parallel_apply(replicas, device_ids, inputs, kwargs)
        return self.gather(outputs, self.output_device)

    def parallel_apply(self, replicas, device_ids, inputs, kwargs):
        return parallel_apply(replicas, inputs, kwargs, device_ids)

    def scatter(self, inputs, kwargs, device_ids):
        bsz = inputs[0].size(self.dim)
        num_dev = len(self.device_ids)
        gpu0_bsz = self.gpu0_bsz
        bsz_unit = (bsz - gpu0_bsz) // (num_dev - 1)
        if gpu0_bsz < bsz_unit:
            chunk_sizes = [gpu0_bsz] + [bsz_unit] * (num_dev - 1)
            delta = bsz - sum(chunk_sizes)
            for i in range(delta):
                chunk_sizes[i + 1] += 1
            if gpu0_bsz == 0:
                chunk_sizes = chunk_sizes[1:]
        else:
            return super().scatter(inputs, kwargs, device_ids)
        return scatter_kwargs(inputs, kwargs, device_ids, chunk_sizes, dim=self.dim)

you can see, in the code BalancedDataParallel inherited the torch. The nn. DataParallel, through the custom after 0, the size of the card batch_size gpu0_bsz, namely 0 card a bit less data. Balance the memory usage of 0 CARDS with other CARDS. The invocation code is as follows:

import BalancedDataParallel

 if n_gpu > 1:
    model = BalancedDataParallel(gpu0_bsz=2, model, dim=0).to(device)
    # model = torch.nn.DataParallel(model)

gpu0_bsz: 0 card batch_size of GPU;
model: model;
dim: batch dimension

as a result, we might as well just batch_size set to 8, namely gpu0_bsz = 2 try, the results are as follows:

the batch_size from 6 to 8 of success, because 0 put a batch less, therefore, will be smaller than the other CARDS. But sacrificing the video memory of one card to the video memory of others, eventually increasing the batch_size, is still available. The advantages of this method are even more obvious when the number of CARDS is large.

[NLP] NameError in using nltk: name ‘freqdist’ is not defined

The author also began to learn NLP technology in order to do graduation design, and wrote out some problems or experiences I met in daily life. For everyone to study and progress together!

recently encountered this problem “NameError: name ‘FreqDist’ is not defined” while learning python natural language to work with the book. The solution is as follows:

from NLTK import * or from nltk.book import * .

operating results will return to normal: