##
# List prepend test
##

import math

list_1 = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
print(f"Before prepend list_1 : {list_1}")
list_1[:0] = [666]
print(f"After prepend list_1 : {list_1}")
list_1 = [665] + list_1
print(f"After prepend list_1 : {list_1}")
list_1[:] = 664, *list_1
print(f"After prepend list_1 : {list_1}")
list_1.insert(0, 663)
print(f"After prepend list_1 : {list_1}")
list_1.insert(2, 664.5)
print(f"After insert list_1 : {list_1}")
list_1[4:4] = 655.5,
print(f"After insert list_1 : {list_1}")

print("-=-" * 25)
# Square all digits using a generator
print([x ** 2 for x in range(10)])
# Square all even digits
print([(x, x ** 2) for x in range(10) if not x % 2])
# this expression is a generator
gee = (x * 2 for x in range(10))
print(next(gee))  # first element
print(next(gee))  # second element
print(*gee)  # remaining elements

t = ("hello", None)
print(t)
u = ("hello",)
v = ("hello",)

print(t == v, u == v)
a = set('tyler')
b = set('nol')
print("Set Diff:", a - b)
print("Set Union:", a | b)
print("Set intersection:", a & b)
print("Set XOR", (a | b) - (a & b))
print("Set XOR", a ^ b)

# zip joins two lists sequentially
q = ['name', 'quest', 'favorite color']
a = ['lancelot', 'the holy grail', 'blue']
for k, v in zip(q, a):
    print(k, v)
print(dict(zip(q, a)))

# filtering a list using agenrator
raw_data = [56.2, float('NaN'), 51.7, 55.3, 52.5, float('NaN'), 47.8]
filtered_data = [(k + 1) for k in raw_data if not math.isnan(k)]
print("Filtered data is ", filtered_data)

# are sets usable as dicts?
s = {"a", "b"}
print(s, type(s))
try:
    print(s.keys(), s.items())
except:
    print("calling .keys() or .items() will fail")
    try:
        s["a"] = 0
    except:
        print("assigning values to a set will also fail")

print(s, type(s))

try:
    print (None < "b")
except TypeError:
    print ("Comparing objects of different types with < or > is legal provided that the objects have appropriate comparison methods")