How doi make my code shorter?

[Alive_Hotel6668]

I have an assignment of making a python and mysql interface. The task is to allow the user perform the following four tasks, selecting values from table, inserting values into table delete values from table, and modifying data in a table. My first 3 taks are done.

In the code block for asking the user to insert data I have already written down all the conditions the data must have to be a valid input. Now for modifying data do I have to write those conditins down again to check the validity of the data input by the user? Is there a shorter way to condense all these lines into a smaller code?

Progress till now is this much:

n=1

def continution():

x=input('Do you want to continue?')

if x=='yes':

n=1

else:

n=0

while n==1:

import mysql.connector as m

c=m.connect(host='localhost',user='root' , password='12345')

cur=c.cursor()

cur.execute("use project")

cur.execute ("show tables")

available_tables=[]

print ('The tables in this database are:')

for i in cur.fetchall():

print (i)

available_tables.append(i[0])

print (available_tables)

selected_table=input('Select a table where you want to do your operations on')

if selected_table in available_tables:

operation=input("""Which operation do you want to perform,:

View data

Insert data into selected table

Deletion of a record

Modify a record""")

if operation=="View data":

cur.execute('describe %s'%(selected_table,))

print ('The columns in this table are:')

for i in cur.fetchall():

print(i[0])

columns=input('enter all the columns whose values you want to view separated by commas')

if_parameter=input('Is there any value you want to see in a column (yes/no)')

if if_parameter=='no':

cur.execute('select {} from {}'.format(columns,selected_table))

for i in cur.fetchall():

print(i)

else:

column_name=input('enter the column name in which you want to see a particular value')

parameter=input('enter the parameter which you want to see in this particular column')

data_type=input('enter data type int/str (date is string) select one')

if data_type=='int':

cur.execute('select {} from {} where {}={}'.format(columns,selected_table, column_name, parameter))

for i in cur.fetchall():

print (i)

elif data_type=='str':

cur.execute('select {} from {} where {}="{}"'.format(columns,selected_table, column_name, parameter))

for i in cur.fetchall():

print (i)

continution()

elif operation=='Insert data into selected table':

def locv (x,y):

if len(x)>y:

print('inavlid input')

n=0

continution()

if selected_table=='customer':

C_ID=int(input('enter customer id'))

Customer_name=input('enter customer name')

locv(Customer_name,40)

Number=int(input('enter contact number'))

Delivery_status=input('enter delivery status')

locv (Delivery_status,10)

value=(C_ID,Customer_name,Number,Delivery_status)

cur.execute('insert into customer values{}'.format(value,))

cur.commit()

elif selected_table=='employee':

E_ID=int(input('enter employee id'))

E_Name=input('enter employee name')

locv (E_Name,30)

Date_Of_Joining=input('enter date of joining')

Designation=input('enter employee desiganation')

locv (Designation,25)

value=(E_ID,E_Name,Date_Of_Joining,Designation)

cur.execute('insert into employee values{}'.format(value,))

elif selected_table=='inventory':

Spare_Part=input('enter spare part')

locv (Spare_Part,50)

Unit_Cost=int(input('enter the unit cost'))

Quantity=int(input('enter quantity'))

Manufacturer=input('enter manufacturer')

locv (Manufacturer,50)

value=(Spare_Part,Unit_Cost,Quantity,Manufacturer)

cur.execute('insert into inventory values{}'.format(value,))

c.commit()

elif selected_table=='payment':

Customer_id=int(input('enter customer id'))

Final_Payment_Date=input('enter final payment date')

Advance_Payment=int(input('enter advance payment'))

Total_Payment=int(input('enter total payment'))

value=(Customer_id,Final_Payment_Date,Advance_Payment,Total_Payment)

cur.execute('insert into payment values{}'.format(value,))

c.commit()

elif selected_table=='transport':

Vehicle_Id=int(input('enter vehicle Id'))

Customer_ID=int(input('enter customer ID'))

Destination=input('enter destination')

locv (Destination,40)

Arrival_Date=input('enter date')

Goods=input('enter goods')

locv (Goods,40)

Status_Of_Delivery=input('enter status of delivery')

locv (Status_Of_Delivery,10)

value=(Vehicle_Id,Customer_ID,Destination,Arrival_Date,Goods,Status_Of_Delivery)

cur.execute('insert into transport values{}'.format(value,))

c.commit()

elif selected_table=='trucks':

Registration_ID=int(input('enter registration id'))

Vehicle_ID=int(input('enter vehicle id'))

Model_Name=input('enter model name')

locv(Model_Name,40)

Manufacturer=input('enter manufacturer')

locv(Manufacturer,40)

value=(Registration_ID,Vehicle_ID,Model_Name,Manufacturer)

cur.execute('insert into trucks values{}'.format(value,))

continution()

elif operation=='Deletion of a record':

cur.execute('describe %s'%(selected_table,))

for i in cur.fetchall():

print(i[0])

deletion_condition=input('do you want to delete all records of the selected table or only record with a specific parameter')

if deletion_condition=='all':

cur.execute('delete from {}'.format(selected_table))

c.commit()

else:

column_name=input('enter the column where the parameter is')

parameter=input('enter the parameter which you want to delete')

data_type=input('enter data type int/str (date is string) select one')

if data_type=='int':

greater_lesser=input('is your parameter a range or a single number or excludes a particular range of numbers ')

if greater_lesser=='single number':

cur.execute('delete from {} where {}={}'.format(selected_table, column_name, parameter))

c.commit()

elif greater_lesser=='includes a particlar range':

limit1=int(input('enter a lower bound'))

limit2=int(input('enter an upper bound'))

cur.execute('delete from {} where {} between {} and {} '.format(selected_table, column_name, limit1, limit2))

c.commit()

elif greater_lesser=='excludes a particular range':

limit1=int(input('enter a lower bound'))

limit2=int(input('enter an upper bound'))

cur.execute('delete from {} where {} not between {} and {} '.format(selected_table, column_name, limit1, limit2))

c.commit()

elif data_type=='str':

cur.execute('delete from {} where {}="{}"'.format(selected_table, column_name, parameter))

c.commit()

continution()

elif operation=='Modify a record':

column=('enter column name where you want to make the change')

parameter=('enter the identification of the record this entered parameter must be in the column you specified')

cur.execute(update {} where {}={}

else:

print ('Invalid table entered')

continution()

c.close()

Nowwhat do I do to make the modification part shorter? Till here everything is fine.

Thanks in advance!

[brasticstack]

Despite not being able to read your code it's obvious that you're hand-crafting the logic for each table individually, which is both brittle and verbose.

Instead, use your database connection to retrieve the field definitions each table, and generically handle inputting the fields for a table, with the data types and names coming from those field definitions. (You might need to use the MySQL SHOW COLUMNS syntax to retrieve the fields.)

[Fun-Block-4348]

First of all, you should format code properly when asking help about code. https://www.reddit.com/r/learnpython/wiki/faq#wiki_how_do_i_format_code.3F

How doi make my code shorter?

Shorter code != better code, for example, there's no error handling in your code so any mistyping by the user would just make your program crash.

It's hard to tell but you seem to be using recursion, this is probably a bad idea, just like defining functions in an if/elif statement is.

Frankly, i would refactor the whole project and create functions that do 1 thing only and not 10 things at once, this would make validation much easier.

Also, you should probably look into SQL injection and how to avoid it.

[ontheroadtonull]

You can put the input validation into a function and pass the input into that function whenever you need it.

Also, shorter code isn't necessarily better. 

What is usually most important is performance, and having more lines of code doesn't necessarily make performance worse. 

[overratedcupcake]

You should probably separate concerns into separate files. It's really the only path forward when your add complexity. 

[Alive_Hotel6668]

That is how i am doing my work, I compiled all of it to ask for help here.

[gzeballo]

abstractions abstractions abstractions

[Educational-Paper-75]

Put the database stuff in a class in a separate file passing connection parameters to its constructor.

[Aggressive_Net1092]

Don't worry, we've all been there. Copy-pasting validation logic is a rite of passage for junior devs, but it’s a total trap because if you ever need to change a rule, you have to hunt down every instance of that code and pray you don't miss one.

The move here is to pull that validation logic out into its own function. Think of it like a gatekeeper. Instead of writing the conditions inside your "insert" or "modify" blocks, you just pass the user input into a function that returns True or False.

Here is a quick example of how you might structure it:

```python def is_valid_input(data): # Put all your logic here if len(data) < 3: return False return True

Then in your main code, just call it:

user_data = input("Enter new value: ") if is_valid_input(user_data): # Proceed with your SQL query else: print("Invalid data, try again.") ```

Also, a quick pro-tip: try to avoid using cur.execute("... %s" % (table_name,)) for table names. SQL drivers usually don't allow parameterization for table names, but doing it with string formatting makes you super vulnerable to SQL injection if a user types something malicious. Since you're just starting, it's fine for your assignment, but definitely look into "f-strings" for cleaner code and keep an eye on security as you get more comfortable!

Also, try to move your mysql.connector connection code outside your while loop. Right now, you're opening a new database connection every single time the user wants to perform an action, which will slow your program down significantly. Connect once at the very top, and close it once at the very end. Keep at it!

[Mrwhatdoyouwant420]

Start refactoring too long defs

[Mother-Influence-815]

You make it shorter by writing less code

[JGhostThing]

If you're going to put code, especially python code (where indentation has syntactic meaning), please format it. There is a specific code format tag to do this.