Numeric characters, such as 0, 1, 2, etc.

Uppercase and lowercase Latin letters: a~z, A~Z

Chinese characters

Some other printable characters, such as: !@#

Special characters, such as spaces and newlines

Variables are usually named with meaningful identifiers Day_of_year,ID_number

Identifier naming rules in Python: It consists of uppercase and lowercase English letters, Chinese characters, numbers, and underscores; Starting with English letters, Chinese characters, and underscores, the length is arbitrary, and it is case-sensitive; Cannot have the same name as a python keyword.

Such as False, def, if, else, etc.

Python objects

type of data

expression

statement

Comment

<variable> =<expression>

Created with "" or ''

Input statement, <variable>=input(<prompt text string>)

Output statement, print(value, ..., sep=' ', end=' ')

Formatted output, 'format control string'% (value sequence)

Formatting function format, "<output string>".format (parameter list)

Built-in module, <function name> (parameter sequence)

Non-built-in modules

analyse problem

design algorithm

Programming

Commissioning

Single branch, if

Double branch, if, else

Multiple branches, if, elif, else

while loop

for loop

break and continue

Modules refer to relatively independent units that provide specific functions and have the characteristics of independence, abstraction, interchangeability, flexibility, etc.

The definition of a function includes the function name, formal parameters, and function body. The syntax for defining a function is as follows: def function name (parameter list): function body

The essence of parameter passing

Default parameters

variable parameter

global variables

local variables

global statement declares global variables

definition

as arguments to higher-order functions

Features

Yuanzu

list

Sequence operations

Sequence functions, such as max, min, etc.

Logical judgment operation, in/not in

Traversal operation, for x in

Created using {} or set()

Creation form: d = {key1:value1, key2:value2,…}, d = dict(key1=value1, key2=value2,…)

open a file

close file

Read data

Write data to file

Create ndarray

Adjust array size

Create special array

Functions that create sequences

numpy.nditer

Conditional operation

Calculations

Create: pd.Series(data, index)

Create: DataFrame([data, index, columns, dtype, copy])

Access the DataFrame object

Modify DataFrame data