BUG: import error with python>=3.6.x since 0.23.0
#### Code Sample, a copy-pastable example if possible

```python
import sys
print(sys.version)

import pandas as pd
```

#### Problem description

It appears to work fine on python 3.5.5 but not on 3.6.5 or 3.7.0

```python
3.7.0 (default, Jul  6 2018, 14:29:43)
[Clang 9.0.0 (clang-900.0.39.2)]

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/mingli/.virtualenvs/test/lib/python3.7/site-packages/pandas/__init__.py", line 23, in <module>
    from pandas.compat.numpy import *
  File "/Users/mingli/.virtualenvs/test/lib/python3.7/site-packages/pandas/compat/__init__.py", line 447, in <module>
    re_type = typing.re.Pattern
AttributeError: module 'typing' has no attribute 're'
```

#### Expected Output

```python
3.7.0 (default, Jul  6 2018, 14:29:43)
[Clang 9.0.0 (clang-900.0.39.2)]
```

#### Output of ``pd.show_versions()``
