Excel data analysis day1

latest revision time：2021/1/16

Abstract: The notes this time are derived from the notes I took when I studied the 2020 Excel Data Analysis Course of Qianfeng Education. There is a video on station B, and you can find the corresponding QQ contacts through station B. This is also considered to be a vain prostitute. Let's advertise for them. There are notes in the courseware. The meaning of note-taking is to pick out the knowledge points that I don't know, and type it again as a memory. Citation knowledge points are relatively trivial, so there is no good directory structure

Excel、SQL、Python

• The advantage of Excel is flexibility, low threshold, and visualization, but up to 100w pieces of data
• The advantage of SQL is that the data is huge and can be monitored in real time, but it cannot be visualized and has performance bottlenecks
• The advantage of Python is: almost all data analysis work can be completed, but the disadvantage is the high cost of learning
• Note: Using SQL to fetch data and Excel for analysis is still very advantageous in terms of flexibility. It is suitable for writing daily and weekly reports. Python code is suitable for high repeatability. Of course, you can do everything if you are familiar with it.
• Excel data analysis needs to meet the requirements of the red circle in the figure below
  

Excel file name

1. An Excel file is called a workbook, and a workbook has many worksheets

Excel extension

Have tested the
interview questions 1. xls, version 97-03, can have macros
2. xlsx, version 07-16, can not have macros
3. xlsm, version 07-16, can have macros

Excel file encryption

Many files for data analysis need to be encrypted

1. Encryption of workbook, file-information-protection workbook-use password for encryption
   1. How to cancel the encryption of the workbook? File-information-just delete the password
2. Encryption and review of worksheets-protection of workbooks (the data structure is protected and the data can be modified)
3. Encryption of the cell, the cell can only be encrypted after it is locked
   1. Encrypt all cells, review-protect the worksheet
   2. Some cells are encrypted, don’t lock the ones you don’t need, lock the ones you need, and then review-protect the worksheet
   3. Note: all locked by default

Custom list

1. File-Options-Advanced-Edit Custom List-New Sequence-Add-OK
   1. English comma

Fill handle

1. Text + number, automatic growth;
2. Number + text, automatic growth;
3. Number filling is repeated unless the Ctrl key is pressed;
4. How to fill the arithmetic sequence?
   1. Method 1: Right-click and pull down, and after releasing, select the sequence-equal difference sequence
   2. Method 2: Start-Edit-Fill (select first)
   3. Method 3: Fill in two numbers by yourself, after it becomes a solid filling handle, double click it
5. Fill in weekdays, fill in months, fill in years-all are filled with right-click to select
6. Double click to fill in quickly

Multiple discontinuous cells are filled with the same data

• Select the desired cell (use shift continuously, use Ctrl when discontinuous)
• enter
• Ctrl+Enter

Text memory input method

• Purpose: If someone fills in the form, then copy it directly
• Usage: Right click-select from the drop-down list
• Note: only suitable for text

Data verification (very important)

• Location: Data-Data Tools-Data Verification-Data Verification-Select Sequence -Select Range

Custom format

Digital fast input

• Requirement: input 1, display as male, input 0, display as female;
• Method: first select the cell-right click-set the cell format-custom-[=1]"Male";[=0]"Female"

Quick completion

1. General format characters + double quotation marks, put content inside double quotation marks
2. If it is a number, the character is 0, if it is a text, the character is the @ symbol

Digital completion

• Demand: Enter a number, automatically add yuan/year after the number, such as entering 5000, it will display 5000 yuan per year
• Method: select the cell-set the cell format-custom- 0 "yuan/year"

Text completion

• Requirement: Enter the text, automatically add the quarter after the text, such as entering the first, display the first quarter
• Method: Select the cell-set the cell format-customize- @"quarter"

Color distinction of values

[Green] 0.0%; red ; blue , the next two are (), which makes it look like a link. The
default order is: positive; negative; zero; text

Use automatic correction for quick input

• File-options-proofreading-automatic correction options-automatic correction-add
• South Campus-Wenzhou University South Campus, Chashan Street, Ouhai District, Wenzhou City, Zhejiang Province

Importing files

• Data-Import the file, know that it is here
• Since the file (2019 version) has many functions, you can import json files , you can import XML files . Note: HowNet can save the XML file every time you finish marking. I didn't know what software to open before. Now you can open it with Excel.

Import TXT file

• Data-access to external data-self-text (2016 version)
• Data-get external data-from text/CSV (2019 version)
• Note: The key point here is to choose the separator , choose a comma (usually a comma)

Import ACCESS file

• Data——Get data——From the database, after selecting the table, choose Load to at the bottom , and then choose to add as a new worksheet or add to an existing worksheet. If you do not perform the above operations, you will directly add Go to a new worksheet.
  

Excel data types

Types of	Case
text	Name, title, address, etc.
Value	Age, 0,1,
Logical value	True，Flase，0,1

Error value	Error type
[####]	Exceed the cell width
[#VALUE!]	Parameter type error
[#DIV/0!]	The divisor is 0, or the cell referenced by the divisor is empty
[#NAME!]	Cannot be the text or other parameters
[N/A]	There are no available values ​​in the formula, missing targets or parameters
[#REF!]	The reference address is invalid and may have been deleted
[#NULL]	The intersection input in the formula is incorrect
[#ON ONE!]	Invalid number

Text->number

• Method: add, subtract, multiply and divide, minus (two negative signs), VALUE
• Note: The format of the new cell needs to be a regular type. If it is text, it won’t work. After addition, subtraction, multiplication, and division, although some are still text types, they can be calculated.
• Logical value, addition, subtraction, multiplication, division, minus, N function

date

• The standard date format is 2021/1/1, separated by slashes
• The standard date format can be calculated, you can add and subtract numbers
• How to change the non-standard date format?

1. 2020.1.1，
   1. Method 1: Select, find and replace, change. To /, if there is an error of ####, you don’t need to open it manually, just double-click the content.
   2. Method 2: SUBSTITUE (selected cell, "oldformat", "newformat") function, remember that only double quotes can be used, not single quotes
   3. In the Excel world, 1900/1/1 is the first day, remember there is only one 9
2. 980102, -TEXT(VALUE,"##-##-##"), VALUE is the selected cell, if the number appears, the cell format is changed to date type , TEXT is the text type,-is modified to Date type
3. 20140101，
   1. Method 1: Data tab, select column, keep selecting, and finally select date
   2. Method 2: -TEXT (select the cell, "#-00-00")

• How to modify the non-standard time? 122040, -TEXT (selected cell, "00!:00!:00"), the colon in the time, the exclamation point colon is used in the formula to express, the rest are numbers, so use 00 to fill

Clear the first single quote in the cell

Format the empty cells, and then select the desired area.

Quick selection of tables

Ctrl+Shift+arrow keys

Shortcuts to summarize the data above

1. Select first
2. Then ALT+=
3. Summarize to the blank line on the last line. If not, sometimes a row of summary is automatically created

How to drop the first row of Excel without moving-freeze pane

• Method: View-Freeze Pane-First Row/First Column
• How to freeze the first row + first column?
  Freeze a specific cell, the non-label data in the upper left corner, only this one