Day01
- Introduction to Python: Functions, Variables...
# ...
# n1 = 10
# n2 = 20
#
# n3 = -9
#
#
#
# n4 = 100
# if n4 == 200 or 150: # incorrect
# print(True)
# else:
# print(False)
#
# n4 = 100
# if n4 == 200 or n4 == 150:
# print(True)
# else:
# print(False)
#
def divide(num1, num2):
return num1 / num2
def get_score_grade(num1, num2):
total_score = num1 + num2
if total_score >= 50:
grade = "Pass"
else:
grade = "Fail"
return total_score, grade
def main():
# about_type()
# about_immutable_value()
# about_boolean_expr()
# print(divide(10, 20))
# print(divide(20, 10))
# print(divide(num220, num1=10))
# print(divide(10, 20))
score, grade = get_score_grade(40, 30)
print(score, grade)
result = get_score_grade(60, 40)
print(type(result), result)
# v1, v2, v3 = get_score_grade(60, 40) # Error
do_work = divide
print(type(do_work))
print(do_work(10, 20)) # Calling divide with 10, 20
print("End of main")
main()
Day02
- Introduction to Python: Lists, Dictionaries, List Comprehensions...
def about_del():
list1 = [1, 2, 4, 5, 6]
del list1[0]
print(list1)
# Delete by indicating the value
list1.remove(5) # 5 is the value, not index
print(list1)
# pop is similar to remove
value = list1.pop(0) # returns the value and remove it
print(value)
print(list1)
def about_list_del():
list1 = [1, -2, -4, 5, -2, 10]
# Use the loop to go through the list and delete all negative numbers
for idx in range(len(list1)):
if list1[idx] < 0:
del list1[idx]
print(idx, list1)
# After the loop
print(list1)
def about_list_del_backward():
list1 = [1, -2, -4, 5, -2, 10]
last = len(list1) - 1
for idx in range(last, - 1, -1):
if list1[idx] < 0:
del list1[idx]
print(idx, list1)
# After the loop
print(list1)
def about_list_del_2loops():
list1 = [1, -2, -4, 5, -2, 10]
to_be_deleted = []
for idx in range(len(list1)):
if list1[idx] < 0:
to_be_deleted.append(list1[idx])
print(to_be_deleted)
for idx in range(len(to_be_deleted)):
list1.remove(to_be_deleted[idx])
print(list1)
def about_list_comprehension():
inputStr = "12,23,45,78,34"
numbers = []
values = inputStr.split(",")
# Convert each value inside values to int and save to numbers
for v in values:
numbers.append(int(v))
print(numbers)
# Apply list comprehension to get the same result
numbers2 = [int(v) for v in values]
print(numbers2)
numbers3 = [int(v) for v in inputStr.split(",")]
print(numbers3)
def about_list_comprehension2():
raw_data = [12, 45, 23, 123, 132, 20, 98, 101]
valid_data = []
for each_value in raw_data:
if each_value <= 100:
valid_data.append(each_value)
print(valid_data)
valid_data2 = [value for value in raw_data if value <= 100]
print(valid_data2)
def about_sorting():
list1 = [12, 34, 9, 56, 23]
list1.sort()
print(list1)
list1.sort(reverse=True)
print(list1)
list2 = [["Jurong", 40], ["Tampines", 67], ["Climenti", 55]]
list2.sort()
print(list2)
list2.sort(key = sort_by_value)
print(list2)
list2.sort(key = sort_by_last)
print(list2)
def sort_by_value(element):
print(element)
return element[1]
def sort_by_last(sub_list):
return sub_list[2]
def about_dictionary():
visitor = {} # Empty dictionary
visitor["North"] = [700, 200]
visitor["South"] = [400, 250]
visitor["East"] = [200, 100]
visitor["West"] = [100, 20]
# Commonly used methods
print("Using visitor.keys()")
for region in visitor.keys():
print(region)
print(visitor[region])
print("Using visitor.values()")
for v_count in visitor.values():
print(v_count)
print("Using visitor.items()")
for region, count in visitor.items():
print(region, count)
# Calculate the % of member visit in each region
member_visit = []
for region, count in visitor.items():
member_percentage = count[1]/count[0] * 100
member_visit.append([region, member_percentage])
# After the loop
for value in member_visit:
print(value)
# Use list comprehension to get the same result
member_visit2 = [[loc, count[1]/count[0]*100] for loc, count in visitor.items()]
for value in member_visit2:
print(value)
def main():
# about_del()
# about_list_del()
# about_list_del_backward()
# about_list_del_2loops()
# about_list_comprehension()
# about_list_comprehension2()
# about_sorting()
about_dictionary()
print("End of main")
main()
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