Python Datatypes and Storage

Apr 3, 2023

https://www.w3schools.com/python/python_datatypes.asp

• Text Type

  • str

• Numeric Types

  • int, float, complex
  • complex 复数

  a = complex(1) # Passing single parameter 
  b = complex(1,2) # Passing both parameters
  
  (1+0j)
  (1+2j)
  

• Sequence Types

  • list, tuple, range, set

• Mapping Type

  • dict

• Slice: 左闭右开

myset = {"apple", "banana", "cherry"}
myset.add(word)
All elements are unique
A set is a collection which is unordered, unchangeable, and unindexed.
Note: Set items are unchangeable, but you can remove items and add new items.
newtup = tuple(set(tup)–{'PYTHON'}) # 去重同时删除数据项

Python List

Elements can’t be changed

• len
• max
• min
• tuple(seq)

**args

people = {
    "Carter": "+1-617-495-1000",
    "David": "+1-949-468-2750"
}

name = get_string("Name: ")
if name in people:
    number = people[name] # index by first map
    print(f"Number: {number}")

my_dict = {"Name":[],"Address":[],"Age":[]};

my_dict["Name"].append("Guru")
my_dict["Address"].append("Mumbai")
my_dict["Age"].append(30)	
print(my_dict)
{'Name': ['Guru'], 'Address': ['Mumbai'], 'Age': [30]}

Python String