Python Lecture Notes-preface (chicken Soup)

The areas that Python excels in and the frameworks it uses

02 Course Objectives

03 People in this life why try to

04 units in a computer

Bit bit (binary Digits): holds a binary number, which is 0 or 1, the smallest storage unit.
The byte byte:8 is a bits of one byte (B), the most commonly used unit.
1B (bytes) = 8bit
1KB (kilobyte KB) =1024b,
1MB (megabyte megabyte abbreviated as "Mega") =1024KB,
1GB (Gigabyte gigabyte, also known as "gigabit") =1024MB,
1TB (Trillionbyte trillion bytes) =1024GB,
1PB (petabyte petabyte Word ticks byte) =1024TB,
1EB (Exabyte exascale bytes) =1024PB,
1ZB (zettabyte 10 trillion byte ze byte) = 1024x768 EB,
1YB (yottabyte 100 million bytes yao byte) = 1024x768 ZB,
1BB (brontobyte 100 billion bytes) = YB

  1位 = 1bit    8bit = 1byte = 1字节       1024bytes = 1kbytes =1KB  1024个字符，小文档 ，几百k可以表示一张图片    1024KB = 1Million Bytes = 1MB = 1兆 ， 几万字的文档， 大图片    1024MB = 1Gigabytes  ， 一个清晰的电影，不是高清，高清能达到数10个g    1024GB = 1TB  ,    1024TB = 1PB 05 What is the difference between compilation and interpretation?     编译型 = 全部翻译，再执行  ，翻译=编译  ，c,c++      解释型 = 边执行边翻译， python php java c# perl ruby javascript

06 32-bit and 64-bit (32bit and 64bit) system differences

1. For the operating system, 64-bit and 32-bit refers to the maximum memory address space, 32-bit maximum 4GB (2^32), 64-bit theoretically 16GB (2^64), but it is generally 2^48

2, for hardware, 64-bit and 32-bit index according to the width, 64 bits at a time to take 8 bytes Y is 64bit,32 take 4 bytes is 32bit, so theoretically 64 bit than 32 bit performance increased by one times.

In fact, it is not up to the memory to become larger and more addresses to be addressed.

3. For applications, the application is based on operating system and hardware, and the instruction width used varies with system and hardware.

If the same 4GB of memory, configured on the 64GB system and 32GB system, the speed of running that faster? --as fast as

The most common manifestation of 32-bit and 64-bit differences is that 640,000-bit operating systems can support more than 4G of memory. The disadvantage is memory footprint, 64-bit code is more space-intensive than 32-bit code,

Now look at 64-bit operating systems compatible with 32-bit software. Conversely, it is not.

The most essential difference between 32-bit and 64-bit is CPU-determined, and the number of operating-system bits is to see how high the CPU's performance can be. We are now seeing 64-bit CPUs in the market, and 32-bit CPUs are already old-fashioned.

Python Lecture Notes-preface (chicken Soup)