Characteristics of python data type(파이썬 데이터 타입의 특성)

- 영작 공부와 python 공부를 한번에 -

Python has three data types of numbers:

1. Integers(정수)

- Integers are whole number that can be positive, negative, or zero.(음수 양수 0 표현 가능)

- They are represented in Python without a decimal point.(소수점x, 정수만)

- They can be of any length up to the available memory in your computer system.(길이 제한x)

 

2. Floating point numbers(부동 소수점 수)

- They can also be positive, negative, or zero.(음수 양수 0)

- Floating point numbers can repesnt a wider range of values than integer(integer tpye 보단 넓은 range를 커버 가능)

 

3. Complex number(복소수)

- Complex numbers are numbers with a real part and imaginary part.(실수와 허수를 포함하는 수)

- Imaginary part of complex numbers are represented in python using 'j' or 'J'.

- For example they can express 3.1 + 2.7j or 1.2 - 2J.

 

Explanation of String data type in Python:

python are not include char data type, but to be able perform similar tasks

1. Concatenation between string types(문자열 끼리의 연결)

- python supports + operator between strings. for example, 'Hi ' + 'python' = Hi python

2. Slicing:(문자 나누기)

- You can extract a portion of a string using slicing. for example, 'Hi python'[3:8] returns 'python'

3. Length:(문자열 길이)

- You can find the length of a string using the len() function

4. Formatting:(문자열의 formatting)

- you can format a string to include values of other data types using the format() method.

for example, 'My name is {} and I am {} years old'.format('Jack', 26) returns 

'My name is Jack and I am {} years old'.

5. Other methods

- upper(): this method returns a new string with all the characters in uppercase.(대문자 변환)

- lower(): this method is opposite of upper().(소문자 변환)

- strip(): this method removes any leading or trailing whitespace from a string.(공백 제거)

- replace(): this method replaces all occurrences of a specified substring in string.(문자열 특정 문자 변환)

- split(): this method splits a string into a list of substring based on a specified delimiter.(특정 문자를 기준으로 문자열 나누기)

 

Explanation of Lists data type in Python:

 

1. Lists can contain items of defferent data type, including other list:

for example,

my_list = [1, "two", 3.0, ["four", 5]]

- append(): Adds an item to the end of the list.(list맨 뒤에 item추가)

- insert(): Inserts an item at a specific position in the list.(원하는 index에 item추가)

- pop(): Removes and returns the item at a specific position in the list.(원하는 index에서 item추출)

- remove(): Removes the first occurrence of a specified item from the list.(원하는 index의 item삭제)

- sort(): Sorts the items in the list in ascending or descending order.(크기 순서로 정렬 reverse=True면 내림차순)

for example,

my_list = [1, 2, 3, 4, 5]
my_list.append(6)
my_list.insert(3, 3.5)
my_list.pop(0)
my_list.remove(4)
my_list.sort(reverse=True)
print(my_list)

# print => [6, 5, 3.5, 3, 2]

List type's limitations and points to note:(많은 양의 데이터 접근은 deque가 빠르다)

if you need repeatedly remove items from the beginning of a list, it may be more efficient to use a data structure like a deque. (deque is double-ended queue)