pd.read_csv  return wrong number of lines
#### Code Sample, a copy-pastable example if possible

```python
# Your code here
import pandas as pd
df_name = pd.read_csv(r"D:\linux\W\NCBI\taxonamy\names.dmp",sep = "\t", header=None)
print(df_name.shape)

```
#### Problem description
We can download a file of the taxonomy from NCBI (https://ftp.ncbi.nlm.nih.gov/pub/taxonomy/taxdump.tar.gz). After extract the file, there is one file named "names.dmp". It is a file with 2704156 lines. When read it with pandas.read_csv with the code
```
df_name = pd.read_csv(r"D:\linux\W\NCBI\taxonamy\names.dmp",sep = "\t", header=None)
print(df_name.shape)
```
the print out is '(2704128, 8)'.
When read it with the code
```
df_name = pd.read_csv(r"D:\linux\W\NCBI\taxonamy\names.dmp",sep = "\t", header=None,engine ="python")
print(df_name.shape)
```
we got error message.  
```

  File "C:\P\Anaconda3\lib\site-packages\pandas\io\parsers.py", line 2685, in _alert_malformed
    raise ParserError(msg)

ParserError: '	' expected after '"'
```
With the code
```
df_name = pd.read_csv(r"D:\linux\W\NCBI\taxonamy\names.dmp",sep = "\t|\t", header=None)
print(df_name.shape)
```
I got
```
__main__:1: ParserWarning: Falling back to the 'python' engine because the 'c' engine does not support regex separators (separators > 1 char and different from '\s+' are interpreted as regex); you can avoid this warning by specifying engine='python'.
(2704156, 8)
```
With the code 
```
df_name = pd.read_csv(r"D:\linux\W\NCBI\taxonamy\names.dmp",sep = "\t\|\t", header=None)
print(df_name.shape)
```
I got
```
__main__:1: ParserWarning: Falling back to the 'python' engine because the 'c' engine does not support regex separators (separators > 1 char and different from '\s+' are interpreted as regex); you can avoid this warning by specifying engine='python'.
(2704156, 4)
```

why some lines were missing in the first method?

[this should explain **why** the current behaviour is a problem and why the expected output is a better solution.]

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#### Expected Output

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

<details>

[paste the output of ``pd.show_versions()`` here below this line]
INSTALLED VERSIONS
------------------
commit: None
python: 3.6.4.final.0
python-bits: 64
OS: Windows
OS-release: 10
machine: AMD64
processor: Intel64 Family 6 Model 94 Stepping 3, GenuineIntel
byteorder: little
LC_ALL: None
LANG: en
LOCALE: None.None

pandas: 0.22.0
pytest: 3.3.2
pip: 9.0.1
setuptools: 38.4.0
Cython: 0.27.3
numpy: 1.14.0
scipy: 1.0.0
pyarrow: None
xarray: None
IPython: 6.2.1
sphinx: 1.6.6
patsy: 0.5.0
dateutil: 2.6.1
pytz: 2017.3
blosc: None
bottleneck: 1.2.1
tables: 3.4.2
numexpr: 2.6.4
feather: None
matplotlib: 2.1.2
openpyxl: 2.4.10
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 1.0.2
lxml: 4.1.1
bs4: 4.6.0
html5lib: 1.0.1
sqlalchemy: 1.2.1
pymysql: None
psycopg2: None
jinja2: 2.10
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: None

and

INSTALLED VERSIONS
------------------
commit: None
python: 3.6.4.final.0
python-bits: 64
OS: Linux
OS-release: 3.10.0-862.6.3.el7.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: zh_CN.UTF-8
LOCALE: zh_CN.UTF-8

pandas: 0.23.0
pytest: 3.5.1
pip: 10.0.1
setuptools: 39.1.0
Cython: 0.28.2
numpy: 1.14.3
scipy: 1.1.0
pyarrow: None
xarray: None
IPython: 6.4.0
sphinx: 1.7.4
patsy: 0.5.0
dateutil: 2.7.3
pytz: 2018.4
blosc: None
bottleneck: 1.2.1
tables: 3.4.3
numexpr: 2.6.5
feather: None
matplotlib: 2.2.2
openpyxl: 2.5.3
xlrd: 1.1.0
xlwt: 1.3.0
xlsxwriter: 1.0.4
lxml: 4.2.1
bs4: 4.6.0
html5lib: 1.0.1
sqlalchemy: 1.2.7
pymysql: None
psycopg2: None
jinja2: 2.10
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: None
</details>
