Hello,

I have been using TQDM for quite a while now with a lot of pleasure. However after running a python script this morning, TQDM has started to generate a error and cannot write anything anymore. I have tried to resolve the issue by reinstalling tqdm without succes. I couldn't found any solution to this problem, so I hope you guys can give a clue to what the problem is.

OS: MacOSX 10.12
Python 3.6.1 |Anaconda 4.4.0 (x86_64)| (default, May 11 2017, 13:04:09)
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)] on darwin

$conda list |grep tqdm
tqdm 4.18.0
tqdm 4.18.0 py_0 conda-forge

Code:
from tqdm import tqdm
tqdm.write("hello")
Traceback (most recent call last):
File "", line 1, in
File "/Users/john-melle/anaconda/lib/python3.6/site-packages/tqdm/_tqdm.py", line 497, in write
with cls.external_write_mode(file=file, nolock=nolock):
File "/Users/john-melle/anaconda/lib/python3.6/contextlib.py", line 82, in enter
return next(self.gen)
File "/Users/john-melle/anaconda/lib/python3.6/site-packages/tqdm/_tqdm.py", line 512, in external_write_mode
cls._lock.acquire()
AttributeError: type object 'tqdm' has no attribute '_lock'