Python Web -L05 (List Comprehension)

# simply function
old_list = ['this','is','a','man']
new_list = []
for item in old_list:
    if len(item) > 2:
        new_list.append(item[::-1])
# list comprehension
# new_list = [expression action, for loop, filter]
new_list = [item[::1] for item in old_list if len(item) > 2]
print(new_list)

###################################################
def temp():
    new_list = []
    for i in range(10):
        new_list.append(i**2)
    return new_list
    
# nested for loop, we can copy the for loop order
print(temp())
x = [i**2 for i in range(10)]
print("x value is ",x)

l = []
for i in range(5):
    for j in range(5):
        for k in range(5):
            l.append((i,j,k))
            #print(l)
l = [(i,j,k) for i in range(5) for j in range(5) for k in range(5)]
print(l)

l = []
for i in range(5):
    for j in range(5):
        for k in range(5):
            if i == j:
                l.append((i,j,k))
l = [(i,j,k) for i in range(5) for j in range(5) for k in range(5) if i == j]
print(l)

# ex 1
l = []
for i in range(1,6):
    if i % 2 == 0:
        for j in range(1,6):
            if j % 3 == 0:
                l.append((i,j))
l = [(i,j) for i in range(1,6) if i % 2 == 0 \
for j in range(1,6) if j % 3 == 0] # "\" connect to next line
print(l)

#ex 2
l = []
for i in range(1,6):
    for j in range(1,6):
        if i % 2 == 0:
            if j % 3 == 0:
                l.append((i,j))
l = [(i,j) for i in range(1,6) for j in range(1,6) if i % 2 == 0 if j % 3 == 0]
print(l)

#ex 3
#l = []
for i in range(1,6):
    for j in range(1,6):
        if i % 2 == 0 and j % 3 == 0:
            l.append((i,j))
l = [(i,j) for i in range(1,6) for j in range(1,6) if i % 2 == 0 and j % 3 == 0]
print(l)