What version am I using?

Python3

use pymongo
print(f'pymongo version {pymongo.version}')
print(f'C extension installed {pymongo.has_c()}')

MongoDB server

$ mongo
> db.version()

Increment numeric value

replace.set age
> db.customers.update({first_name:"John",last_name:"Doe"},
                       {$set:{age:45}})

add 5 years to age                    
> db.customers.update({first_name:"John",last_name:"Doe"},
                       {$inc{age:5}}})                     

Sort by last name

> db.customers.find(...).sort({last_name:1})       <-- 1 is ascending order

> db.customers.find(...).sort({last_name:-1})      <-- -1 is descending order

> db.customers.find(...).sort(...).pretty()

Count documents

count all
> db.customers.find().count()

Count selected documents
> db.customers.find(...).count()

limit returned documents

> db.customers.find(...).limit(4)

Iterate thru "stuff"

> db.customers.find().forEach(
               function(doc)
               {print("Customer Name: "+doc.last_name)})

Create a user for this database

> db.createUser({ user:"name",
                pwd:"password",
                roles: ["readwrite","dbAdmin"] })

Regular expressions

lastname contains character 'e'
> db.phones.find( {lastname: {$regex: /e/}})
> db.phones.find( {lastname: {$regex: 'e'}})
> db.phones.find( {lastname: /e/})

lastname does not contains character 'e'
> db.phone.find(Lastname; {$not: /e/}})

Select returned fields

return all entries and all fields
> db.phones.find()
> db.phones.find({})

return all fields for entries with lastname = "Pete"
> db.phones.find({lastname: "Pete"})

only return field age for entries with lastname = "pete"
_id is automatically returned
> db.phones.find( {lastname: "Pete"},{age: 1})

only return field age for entries with lastname = "pete"
_id is not returned
> db.phones.find( {lastname: "Pete"},{age: 1, _id: 0})

only return field age for entries with lastname = "pete"
_id is not returned
> db.phones.find( {lastname: "Pete"},{_id: 0})

Project Fields to Return from Query

Select documents missing age field

db.phone.find(age: {$exists:false}})

db.phone.find(age: {$exists:false}}).count()

db.phone.find(age: {$exists:false}}).pretty()