#Django_ORM #Database
Convert existing databases to Django models
or
Convert existing databases to Django models
python manage.py inspectdb
or
python manage.py inspectdb > models.py
#Django_ORM #Database
Rename column name in Database Table:
` a = models.CharField(max_length=40,db_column='column1')`
Rename column name in Database Table:
` a = models.CharField(max_length=40,db_column='column1')`
Note!!!
Use comments liberally not just for yourself, but for anyone else who might have to maintain or enhance your code in the future!!
Use comments liberally not just for yourself, but for anyone else who might have to maintain or enhance your code in the future!!
SearchVector
For searching several fields by annotating to one field
For searching several fields by annotating to one field
>> from django.contrib.postgres.search import SearchVector
>>> Entry.objects.annotate(
... search=SearchVector('body_text', 'blog__tagline'),
... ).filter(search='Cheese')
[<Entry: Cheese on Toast recipes>, <Entry: Pizza Recipes>]
#working_with_files
Title: Reading Files
Builtin operator
instead of :
can use:
Title: Reading Files
Builtin operator
with
in python will automatically close the file when you are done processing it.instead of :
handle = open("test.txt")
can use:
with open("test.txt") as file_handler
Clean Code Principles
✅Code should be elegant and pleasing to read.
✅No duplication should be allowed. Use DRY (Don't Repeat Yourself)
✅Code should be covered with tests.
✅Every function should do one thing and do it well.
✅Codebase should contain only code that is needed.
✅Code should be elegant and pleasing to read.
✅No duplication should be allowed. Use DRY (Don't Repeat Yourself)
✅Code should be covered with tests.
✅Every function should do one thing and do it well.
✅Codebase should contain only code that is needed.
#compare
all() and any()
all() method demonstrates if List1 has List2 elements
all() and any()
all() method demonstrates if List1 has List2 elements
# List1
List1 = ['python' , 'javascript', 'csharp', 'go', 'c', 'c++']
# List2
List2 = ['csharp1' , 'go', 'python']
check = all(item in List1 for item in List2)
any() checks if the list contains any elements of another one:# List1
List1 = ['python' , 'javascript', 'csharp', 'go', 'c', 'c++']
# List2
List2 = ['swift' , 'php', 'python']
check = any(item in List1 for item in List2)
Time module
time.ctime() - converts a time in seconds since the epoch to a string representing local time ( For Unix systems, the epoch was in 1970).
time.sleep() - suspend execution of your script a given number of seconds like a pause.
time.strftime - create a string that represents the time in a more human readable format.
time.time - returns the time in seconds since the epoch as a floating point number.
time.ctime() - converts a time in seconds since the epoch to a string representing local time ( For Unix systems, the epoch was in 1970).
time.sleep() - suspend execution of your script a given number of seconds like a pause.
time.strftime - create a string that represents the time in a more human readable format.
time.time - returns the time in seconds since the epoch as a floating point number.
A "decorator" takes the function below and does something with it
Builtin decorators
@classmethod
✅Declares a class method.
✅The first parameter must be cls, which can be used to access class attributes.
✅The class method can only access the class attributes but not the instance attributes.
✅The class method can be called using ClassName.MethodName() and also using object.
Source_link
Builtin decorators
@classmethod
✅Declares a class method.
✅The first parameter must be cls, which can be used to access class attributes.
✅The class method can only access the class attributes but not the instance attributes.
✅The class method can be called using ClassName.MethodName() and also using object.
Source_link