How can I insert values at the start of an array of vectors in Blender 2.8 using Python How can I insert a value in a array of vectors using Python 3.x? 

The full code is below.  It is using Blender 2.82a:

import bpy
import mathutils
import math

ob = bpy.context.object

#1) Get all vertexes and place in vector array
vec = [v.co for v in ob.data.vertices]

print("vec=%s" % vec)


It creates an array of Vectors of x,y,z values:

vec=[Vector((1.0, 1.0, 1.0)), Vector((1.0, 1.0, -1.0)), Vector((1.0, -1.0, 1.0)), Vector((1.0, -1.0, -1.0)), Vector((-1.0, 1.0, 1.0)), Vector((-1.0, 1.0, -1.0)), Vector((-1.0, -1.0, 1.0)), Vector((-1.0, -1.0, -1.0))]


And I would like to insert a 7 at the start of each vector so it would look like:

vec=[Vector((7, 1.0, 1.0, 1.0)), Vector((7, 1.0, 1.0, -1.0)), Vector((7, 1.0, -1.0, 1.0)), Vector((7, 1.0, -1.0, -1.0)), Vector((7, -1.0, 1.0, 1.0)), Vector((7, -1.0, 1.0, -1.0)), Vector((7, -1.0, -1.0, 1.0)), Vector((7, -1.0, -1.0, -1.0))]


The .insert doesn't seem to work in vectors.
By default Vertices vectors are in 3 dimensions so we need to create a new one with 4 dimensions.

import bpy
from mathutils import Vector

try:
    vectors = [Vector((7.0, v.co.x, v.co.y, v.co.z)) for v in bpy.context.object.data.vertices]    
    print(vectors)
except AttributeError:
    print('Please select a mesh object')


Result :