We will learn how to read a CSV file in Python in this shot. Let's start by understanding what a CSV file is.

##   
### What is a CSV file?
* A **CSV file** is a comma-separated values file.
* Information is organized in tabular form.
* The delimiter doesn't need to be a comma `,` because there are other delimiters such as tab `\t`, the colon `:`, and semi-colon `;`.




### Sample CSV file
```
EMPLOYEE_ID,FIRST_NAME,LAST_NAME

198,Donald,OConnell

199,Douglas,Grant

200,Jennifer,Whalen
```

EMPLOYEE_ID,FIRST_NAME,LAST_NAME,EMAIL,PHONE_NUMBER,HIRE_DATE,JOB_ID,SALARY,COMMISSION_PCT,MANAGER_ID,DEPARTMENT_ID
198,Donald,OConnell,DOCONNEL,650.507.9833,21-JUN-07,SH_CLERK,2600, - ,124,50
199,Douglas,Grant,DGRANT,650.507.9844,13-JAN-08,SH_CLERK,2600, - ,124,50
200,Jennifer,Whalen,JWHALEN,515.123.4444,17-SEP-03,AD_ASST,4400, - ,101,10
201,Michael,Hartstein,MHARTSTE,515.123.5555,17-FEB-04,MK_MAN,13000, - ,100,20
202,Pat,Fay,PFAY,603.123.6666,17-AUG-05,MK_REP,6000, - ,201,20
203,Susan,Mavris,SMAVRIS,515.123.7777,07-JUN-02,HR_REP,6500, - ,101,40
204,Hermann,Baer,HBAER,515.123.8888,07-JUN-02,PR_REP,10000, - ,101,70
205,Shelley,Higgins,SHIGGINS,515.123.8080,07-JUN-02,AC_MGR,12008, - ,101,110
206,William,Gietz,WGIETZ,515.123.8181,07-JUN-02,AC_ACCOUNT,8300, - ,205,110
100,Steven,King,SKING,515.123.4567,17-JUN-03,AD_PRES,24000, - , - ,90
101,Neena,Kochhar,NKOCHHAR,515.123.4568,21-SEP-05,AD_VP,17000, - ,100,90
102,Lex,De Haan,LDEHAAN,515.123.4569,13-JAN-01,AD_VP,17000, - ,100,90
103,Alexander,Hunold,AHUNOLD,590.423.4567,03-JAN-06,IT_PROG,9000, - ,102,60
104,Bruce,Ernst,BERNST,590.423.4568,21-MAY-07,IT_PROG,6000, - ,103,60
105,David,Austin,DAUSTIN,590.423.4569,25-JUN-05,IT_PROG,4800, - ,103,60
106,Valli,Pataballa,VPATABAL,590.423.4560,05-FEB-06,IT_PROG,4800, - ,103,60
107,Diana,Lorentz,DLORENTZ,590.423.5567,07-FEB-07,IT_PROG,4200, - ,103,60
108,Nancy,Greenberg,NGREENBE,515.124.4569,17-AUG-02,FI_MGR,12008, - ,101,100
109,Daniel,Faviet,DFAVIET,515.124.4169,16-AUG-02,FI_ACCOUNT,9000, - ,108,100
110,John,Chen,JCHEN,515.124.4269,28-SEP-05,FI_ACCOUNT,8200, - ,108,100
111,Ismael,Sciarra,ISCIARRA,515.124.4369,30-SEP-05,FI_ACCOUNT,7700, - ,108,100
112,Jose Manuel,Urman,JMURMAN,515.124.4469,07-MAR-06,FI_ACCOUNT,7800, - ,108,100
113,Luis,Popp,LPOPP,515.124.4567,07-DEC-07,FI_ACCOUNT,6900, - ,108,100
114,Den,Raphaely,DRAPHEAL,515.127.4561,07-DEC-02,PU_MAN,11000, - ,100,30
115,Alexander,Khoo,AKHOO,515.127.4562,18-MAY-03,PU_CLERK,3100, - ,114,30
116,Shelli,Baida,SBAIDA,515.127.4563,24-DEC-05,PU_CLERK,2900, - ,114,30
117,Sigal,Tobias,STOBIAS,515.127.4564,24-JUL-05,PU_CLERK,2800, - ,114,30
118,Guy,Himuro,GHIMURO,515.127.4565,15-NOV-06,PU_CLERK,2600, - ,114,30
119,Karen,Colmenares,KCOLMENA,515.127.4566,10-AUG-07,PU_CLERK,2500, - ,114,30
120,Matthew,Weiss,MWEISS,650.123.1234,18-JUL-04,ST_MAN,8000, - ,100,50
121,Adam,Fripp,AFRIPP,650.123.2234,10-APR-05,ST_MAN,8200, - ,100,50
122,Payam,Kaufling,PKAUFLIN,650.123.3234,01-MAY-03,ST_MAN,7900, - ,100,50
123,Shanta,Vollman,SVOLLMAN,650.123.4234,10-OCT-05,ST_MAN,6500, - ,100,50
124,Kevin,Mourgos,KMOURGOS,650.123.5234,16-NOV-07,ST_MAN,5800, - ,100,50
125,Julia,Nayer,JNAYER,650.124.1214,16-JUL-05,ST_CLERK,3200, - ,120,50
126,Irene,Mikkilineni,IMIKKILI,650.124.1224,28-SEP-06,ST_CLERK,2700, - ,120,50
127,James,Landry,JLANDRY,650.124.1334,14-JAN-07,ST_CLERK,2400, - ,120,50
128,Steven,Markle,SMARKLE,650.124.1434,08-MAR-08,ST_CLERK,2200, - ,120,50
129,Laura,Bissot,LBISSOT,650.124.5234,20-AUG-05,ST_CLERK,3300, - ,121,50
130,Mozhe,Atkinson,MATKINSO,650.124.6234,30-OCT-05,ST_CLERK,2800, - ,121,50
131,James,Marlow,JAMRLOW,650.124.7234,16-FEB-05,ST_CLERK,2500, - ,121,50
132,TJ,Olson,TJOLSON,650.124.8234,10-APR-07,ST_CLERK,2100, - ,121,50
133,Jason,Mallin,JMALLIN,650.127.1934,14-JUN-04,ST_CLERK,3300, - ,122,50
134,Michael,Rogers,MROGERS,650.127.1834,26-AUG-06,ST_CLERK,2900, - ,122,50
135,Ki,Gee,KGEE,650.127.1734,12-DEC-07,ST_CLERK,2400, - ,122,50
136,Hazel,Philtanker,HPHILTAN,650.127.1634,06-FEB-08,ST_CLERK,2200, - ,122,50
137,Renske,Ladwig,RLADWIG,650.121.1234,14-JUL-03,ST_CLERK,3600, - ,123,50
138,Stephen,Stiles,SSTILES,650.121.2034,26-OCT-05,ST_CLERK,3200, - ,123,50
139,John,Seo,JSEO,650.121.2019,12-FEB-06,ST_CLERK,2700, - ,123,50
140,Joshua,Patel,JPATEL,650.121.1834,06-APR-06,ST_CLERK,2500, - ,123,50

#importing csv module
import csv

#open csv file and read
with open('employee.csv') as employeeFile:
  read_csv = csv.reader(employeeFile, delimiter = ',')

  #print each row
  for row in read_csv:
    print(row)

##   
### Explanation

* Line 2: Import the `csv` module, which is provided by Python.
* Line 5: Open the CSV file as `employeeFile`.
* Line 6: Read the CSV file with the ``reader()`` method, which accepts a file object and delimiter as parameters.
* Line 9: Loop through the iterator returned by `csv.reader()`.
* Line 10: Print each row. It will print each row as a list.

##   
### Example 2
In this example, we will try to get the info of the employee with ID `198`.

#importing csv module
import csv

#open and read csv file
with open('employee.csv') as employeeFile:
  read_csv = csv.reader(employeeFile, delimiter = ',')
  
  #traverse every row in csv
  for row in read_csv:
    #check for id
    if(row[0] == '198'):
      #print employee
      print(row)

##   
### Explanation
Example 2 is the same as example 1, except that in line 11, we use the ``if`` statement to check if the present employee ID matches the given ID. If they match, we print the employee info.

How to read a Python CSV file

What is a CSV file?

Sample CSV file

Example 1

Explanation

Example 2

Explanation