首页 磁力链接怎么用

Full Stack Data Analyst A-Z BootCamp

文件类型 收录时间 最后活跃 资源热度 文件大小 文件数量
视频 2024-1-10 23:01 2024-11-9 17:48 168 5 GB 134
二维码链接
Full Stack Data Analyst A-Z BootCamp的二维码
种子下载(838888不存储任何种子文件)
种子下载线路1(迅雷)--推荐
种子下载线路2(比特彗星)
种子下载线路3(torcache)
3条线路均为国内外知名下载网站种子链接,内容跟本站无关!
文件列表
  1. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/03 - Managing and Analyzing Data/001 Structure data for optimum usage.mp4159.15MB
  2. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/03 - Managing and Analyzing Data/002 Converting lists to tables.mp4154.95MB
  3. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/002 Uber Loading Dataset and Preparation.mp4150.4MB
  4. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/001 Sorting concepts and sort menu options.mp4139.86MB
  5. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/07 - Advanced Filtering/001 Using Advanced Filter for complex OR criteria.mp4105.65MB
  6. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/002 working with Identifiers in Python.mp496.34MB
  7. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/002 Sorting from menu icons.mp494.14MB
  8. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/008 Use date functions with WHERE.mp492.02MB
  9. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/05 - Creating Automatic Subtotals In Sorted Lists/002 Expanding and collapsing with grouping and outlining symbols.mp488.41MB
  10. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/006 More advanced string functions.mp486.76MB
  11. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/002 Understand SQL Indexes and keys.mp480.39MB
  12. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/004 Sorting based on the order of data in custom lists.mp476.34MB
  13. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/005 Sorting by cell color, font color, or cell icon.mp471.43MB
  14. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/08 - Eliminating Duplicate Data/003 Using an array formula to count the number of unique items in a list.mp470.26MB
  15. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/003 Multiple-key sorting.mp468.15MB
  16. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/06 - Filtering Data/001 Single and multiple-column filtering.mp467.48MB
  17. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/005 Use string functions on your data.mp466.74MB
  18. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/24 - Grouping Your SQL Results/003 De-duplicate with SELECT DISTINCT.mp463.8MB
  19. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/08 - Eliminating Duplicate Data/002 Using a specialized array formula to identify data that's been duplicated.mp461.22MB
  20. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/006 Filtering Data.mp461.2MB
  21. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/24 - Grouping Your SQL Results/001 Use GROUP BY with count.mp460.69MB
  22. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/26 - More Advanced SQL/002 Use functions.mp460.17MB
  23. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/05 - Creating Automatic Subtotals In Sorted Lists/001 Setting up single and multiple-level subtotals.mp458.51MB
  24. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/003 Use LIKE, IN, and wildcards with WHERE.mp458.34MB
  25. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/07 - Advanced Filtering/002 Using Advanced Filter for specialized filters.mp456.59MB
  26. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/26 - More Advanced SQL/003 Use procedures.mp456.34MB
  27. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/001 Retrieve data with SELECT.mp455.77MB
  28. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/005 variables in python.mp452.5MB
  29. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/07 - Advanced Filtering/003 Using Advanced Filter to create unique lists from repeating field data.mp452.4MB
  30. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/002 Filter results with WHERE clause.mp451.3MB
  31. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/26 - More Advanced SQL/001 Use variables.mp451.12MB
  32. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/008 defining input functions in python.mp450.71MB
  33. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/21 - CRUD APPLICATIONS/002 The SELECT Function.mp450.46MB
  34. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/06 - Filtering Data/003 Using date filters.mp450.3MB
  35. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/13 - RELATIONSHIPS/002 Accessing Related Tables.mp449.85MB
  36. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/003 Visualise your database.mp449.78MB
  37. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/10 - SQL INSTALLATION/001 Installing on Windows.mp449.15MB
  38. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/003 Write Comments in python.mp448.77MB
  39. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/06 - Filtering Data/005 Using the Top Ten (value or percent) option.mp448.46MB
  40. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/004 Merge data across tables with JOINS.mp447.59MB
  41. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/13 - RELATIONSHIPS/003 Relating Multiple Tables.mp447.04MB
  42. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/003 performing logic in python.mp446.41MB
  43. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/006 Combine rows with SQL UNION.mp445.74MB
  44. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/24 - Grouping Your SQL Results/002 Filter grouped results with HAVING.mp445.63MB
  45. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/002 The NULL Value.mp443.07MB
  46. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/006 Naming Python Variables.mp442.9MB
  47. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/21 - CRUD APPLICATIONS/001 Embedding SQL.mp442.45MB
  48. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/06 - Filtering Data/006 Creating custom filters.mp442.4MB
  49. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/22 - DATA REPORTING AND ANALYSIS IN SQL/002 Get familiar with phpMyAdmin.mp441.68MB
  50. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/004 performing bitwise manipulations of data in python.mp441.27MB
  51. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/11 - SQL Overview/003 The SELECT Statement.mp439.89MB
  52. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/08 - Eliminating Duplicate Data/001 Using the Remove Duplicates command.mp439.57MB
  53. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/06 - Filtering Data/002 Using text filters.mp439.36MB
  54. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/19 - TRIGGERS/001 Automating Data With Triggers.mp438.62MB
  55. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/06 - Filtering Data/004 Using numeric filters.mp438.27MB
  56. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/006 Text 2.mp437.51MB
  57. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/19 - TRIGGERS/002 Preventing Updates.mp436.02MB
  58. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/005 Overview.mp435.97MB
  59. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/010 Uber Analysis Of Starting Point Of Trips.mp435.35MB
  60. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/01 - Introduction To Data Analysis/003 Modern Data Ecosystem.mp434.67MB
  61. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/18 - TRANSACTIONS/002 Data Integrity.mp434.66MB
  62. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/17 - AGGREGATES/001 What are Aggregates.mp434.63MB
  63. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/003 Constraining Columns.mp434.25MB
  64. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/01 - Introduction To Data Analysis/004 Key Players in the Data Ecosystem.mp433.31MB
  65. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/19 - TRIGGERS/003 Example Timestamps.mp433.17MB
  66. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/006 Uber Analysis Of Purpose Of Trips.mp431.98MB
  67. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/01 - Introduction To Data Analysis/002 Defining Data Analysis.mp429.5MB
  68. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/008 Ordering Output.mp429.36MB
  69. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/008 Select from a selection with subqueries.mp428.79MB
  70. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/009 importing libraries in python.mp428.51MB
  71. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/006 Sorting columns (sorting left-to-right).mp428.07MB
  72. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/20 - VIEWS & SUBSELECTS/001 Creating a Subselect.mp428.02MB
  73. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/20 - VIEWS & SUBSELECTS/004 Creating a Joined View.mp427.84MB
  74. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/21 - CRUD APPLICATIONS/003 INSERT, UPDATE and DELETE Functions.mp427.59MB
  75. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/007 Change report headings with alias.mp427.14MB
  76. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/001 Introduction.mp426.89MB
  77. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/007 Saving & Exporting.mp426.62MB
  78. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/001 Inserting Rows.mp426.6MB
  79. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/007 Removing Duplicates.mp426.32MB
  80. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/20 - VIEWS & SUBSELECTS/002 Searching Within A Result Set.mp426.28MB
  81. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/04 - Sorting Data/007 Sorting data in random order.mp426MB
  82. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/18 - TRANSACTIONS/003 Performance.mp425.34MB
  83. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/24 - Grouping Your SQL Results/004 Merge rows with GROUP BY.mp425.29MB
  84. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/005 ID Columns.mp424.38MB
  85. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/004 Exporting.mp423.81MB
  86. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/14 - STRINGS/003 Selecting Part Of A String.mp423.76MB
  87. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/11 - SQL Overview/004 Selecting Rows.mp423.51MB
  88. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/004 working with strings in python.mp422.99MB
  89. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/005 Understand SQL JOINS.mp422.77MB
  90. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/005 Uber Analysis Of Hot Hour Of Trips.mp422.16MB
  91. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/007 Merge data across tables with IN.mp421.98MB
  92. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/005 assigning variables in python.mp420.9MB
  93. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/20 - VIEWS & SUBSELECTS/003 Creating a View.mp420.68MB
  94. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/22 - DATA REPORTING AND ANALYSIS IN SQL/003 Understand the demo database.mp420.53MB
  95. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/002 Raw.mp420.25MB
  96. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/009 Conditional Expressions.mp419.83MB
  97. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/25 - Merge Data From Multiple Tables/001 Make your queries faster.mp419.68MB
  98. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/12 - FUNDAMENTAL CONCEPTS/004 Changing A Schema.mp419.5MB
  99. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/23 - Use SQL To Report Data/004 Sort SQL results with ORDER BY.mp417.92MB
  100. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/007 assigning members in python.mp417.79MB
  101. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/14 - STRINGS/005 Folding Case.mp416.45MB
  102. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/16 - DATES & TIME/002 Date and Time Related Functions.mp415.6MB
  103. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/11 - SQL Overview/002 Database Organisation.mp415.2MB
  104. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/001 Addition of Data points Python.mp415.15MB
  105. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/003 Uber Analysis Of Categories Of Trips.mp415.15MB
  106. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/11 - SQL Overview/005 Counting Rows.mp413.82MB
  107. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/15 - NUMBERS/002 What Type is That Value.mp413.45MB
  108. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/15 - NUMBERS/003 Integer Division.mp413.18MB
  109. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/14 - STRINGS/002 Finding The Length Of A String.mp413.16MB
  110. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/17 - AGGREGATES/003 Aggregating DISTINCT Values.mp412.77MB
  111. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/09 - MASTER SQL FOR DATA ANALYSIS/002 Understanding SQL.mp412.62MB
  112. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/002 Comparing Strings and variables in Python.mp412.31MB
  113. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/007 Defining output Function.mp411.64MB
  114. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/17 - AGGREGATES/002 Using Aggregate Functions.mp411.53MB
  115. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/007 Uber Analysis Of Day With Highest Number Of Trips.mp410.72MB
  116. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/008 Uber Analysis Of Number Of Trips Per Day.mp410.63MB
  117. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/004 Uber Analysis Of Length Of Trips.mp410.45MB
  118. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/14 - STRINGS/004 Removing Spaces.mp410.25MB
  119. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/29 - Statistical Operations In Python/006 assigning special variables in python.mp49.92MB
  120. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/11 - SQL Overview/001 About SQL.mp49.92MB
  121. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/11 - SQL Overview/006 Deleting Data.mp49.44MB
  122. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/22 - DATA REPORTING AND ANALYSIS IN SQL/001 Introduction.mp49.24MB
  123. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/009 Uber Analysis Of Number Of In The Month.mp49.11MB
  124. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/02 - MASTER EXCEL FOR DATA ANALYSIS/001 Introduction.mp49.09MB
  125. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/27 - Introduction/003 Text.mp49.06MB
  126. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/13 - RELATIONSHIPS/001 Understanding JOIN.mp49.04MB
  127. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/15 - NUMBERS/004 Rounding Numbers.mp48.85MB
  128. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/15 - NUMBERS/001 Numeric Types.mp48.18MB
  129. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/30 - HANDS-ON DATA ANALYSIS PRACTICE WITH PYTHON/001 Introduction.mp47.57MB
  130. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/18 - TRANSACTIONS/001 What are Transactions.mp46.56MB
  131. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/28 - Data Analysis With Python/001 Introduction.mp46.21MB
  132. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/09 - MASTER SQL FOR DATA ANALYSIS/003 How to use the Exercise files.mp46.18MB
  133. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/16 - DATES & TIME/001 Date and Times.mp45.97MB
  134. [TutsNode.com] - Full Stack Data Analyst A-Z™ BootCamp/14 - STRINGS/001 About SQL Strings.mp45.59MB
友情提示
不会用的朋友看这里 把磁力链接复制到离线下载,或者bt下载软件里即可下载文件,或者直接复制迅雷链接到迅雷里下载! 亲,你造吗?将网页分享给您的基友,下载的人越多速度越快哦!

违规内容投诉邮箱:[email protected]

概述 838888磁力搜索是一个磁力链接搜索引擎,是学术研究的副产品,用于解决资源过度分散的问题 它通过BitTorrent协议加入DHT网络,实时的自动采集数据,仅存储文件的标题、大小、文件列表、文件标识符(磁力链接)等基础信息 838888磁力搜索不下载任何真实资源,无法判断资源的合法性及真实性,使用838888磁力搜索服务的用户需自行鉴别内容的真伪 838888磁力搜索不上传任何资源,不提供Tracker服务,不提供种子文件的下载,这意味着838888磁力搜索 838888磁力搜索是一个完全合法的系统