Varför platta filer är viktiga inom datavetenskap

Introduktion till dataimport i Python

Hugo Bowne-Anderson

Data Scientist at DataCamp

Platta filer

titanic.csv

PassengerId,Survived,Pclass,Name,Gender,Age,SibSp,Parch,Ticket,Fare,Cabin,Embarked
1,0,3,"Braund, Mr. Owen Harris",male,22,1,0,A/5 21171,7.25,,S
2,1,1,"Cumings, Mrs. John Bradley",female,38,1,0,PC 17599,71.2833,C85,C
3,1,3,"Heikkinen, Miss. Laina",female,26,0,0,STON/O2.3101282,7.925,,S

Platta filer

titanic.csv

PassengerId,Survived,Pclass,Name,Gender,Age,SibSp,Parch,Ticket,Fare,Cabin,Embarked

1,0,3,"Braund, Mr. Owen Harris",male,22,1,0,A/5 21171,7.25,,S

2,1,1,"Cumings, Mrs. John Bradley",female,38,1,0,PC 17599,71.2833,C85,C

3,1,3,"Heikkinen, Miss. Laina",female,26,0,0,STON/O2.3101282,7.925,,S

                        Name      Sex  Cabin  Survived
     Braund, Mr. Owen Harris     male    NaN         0
  Cumings, Mrs. John Bradley   female    C85         1
      Heikkinen, Miss. Laina   female    NaN         1
Futrelle, Mrs. Jacques Heath   female   C123         1
    Allen, Mr. William Henry     male    NaN         0

Platta filer

titanic.csv

titanic.csv med en markerad rad

                        Name      Sex  Cabin  Survived
     Braund, Mr. Owen Harris     male    NaN         0
  Cumings, Mrs. John Bradley   female    C85         1
      Heikkinen, Miss. Laina   female    NaN         1

Platta filer

titanic.csv

titanic.csv med en markerad kolumn

                        Name      Sex  Cabin  Survived
     Braund, Mr. Owen Harris     male    NaN         0
  Cumings, Mrs. John Bradley   female    C85         1
      Heikkinen, Miss. Laina   female    NaN         1

Platta filer

Textfiler som innehåller poster
Det vill säga tabelldata
Post: rad med fält eller attribut

titanic.csv

PassengerId,Survived,Pclass,Name,Gender,Age,SibSp,Parch,Ticket,Fare,Cabin,Embarked
1,0,3,"Braund, Mr. Owen Harris",male,22,1,0,A/5 21171,7.25,,S
2,1,1,"Cumings, Mrs. John Bradley",female,38,1,0,PC 17599,71.2833,C85,C
3,1,3,"Heikkinen, Miss. Laina",female,26,0,0,STON/O2.3101282,7.925,,S

Platta filer

Textfiler som innehåller poster
Det vill säga tabelldata
Post: rad med fält eller attribut
Kolumn: särdrag eller attribut

titanic.csv

titanic.csv med en markerad rad

Platta filer

Textfiler som innehåller poster
Det vill säga tabelldata
Post: rad med fält eller attribut
Kolumn: särdrag eller attribut

titanic.csv

titanic.csv med en markerad kolumn

Rubrikrad

titanic.csv

________________________________________________________________________
PassengerId,Survived,Pclass,Name,Gender,Age,SibSp,Parch,Ticket,Fare,Cabin,Embarked
________________________________________________________________________
1,0,3,"Braund, Mr. Owen Harris",male,22,1,0,A/5 21171,7.25,,S   
2,1,1,"Cumings, Mrs. John Bradley",female,38,1,0,PC 17599,71.2833,C85,C
3,1,3,"Heikkinen, Miss. Laina",female,26,0,0,STON/O2.3101282,7.925,,S

Rubrikrad

titanic.csv

________________________________________________________________________
PassengerId,Survived,Pclass,Name,Gender,Age,SibSp,Parch,Ticket,Fare,Cabin,Embarked
________________________________________________________________________
1,0,3,"Braund, Mr. Owen Harris",male,22,1,0,A/5 21171,7.25,,S   
2,1,1,"Cumings, Mrs. John Bradley",female,38,1,0,PC 17599,71.2833,C85,C
3,1,3,"Heikkinen, Miss. Laina",female,26,0,0,STON/O2.3101282,7.925,,S

Filtillägg

.csv – Kommaseparerade värden
.txt – Textfil
kommatecken, tabbar – Avgränsare

Tabbavgränsad fil

MNIST.txt

pixel149    pixel150    pixel151    pixel152    pixel153
0           0           0           0           0    
86          250         254         254         254    
0           0           0           9           254    
0           0           0           0           0    
103         253         253         253         253    
0           0           0           0           0    
0           0           0           0           0        
0           0           0           0           41        
253         253         253         253         253

Tabbavgränsad fil

MNIST.txt

pixel149    pixel150    pixel151    pixel152    pixel153
0           0           0           0           0    
86          250         254         254         254    
0           0           0           9           254    
0           0           0           0           0    
103         253         253         253         253    
0           0           0           0           0    
0           0           0           0           0        
0           0           0           0           41        
253         253         253         253         253

MNIST-bild:

Hur importerar du platta filer?

Två viktiga paket: NumPy, pandas

ch_1_2.026.png

Här lär du dig importera:
- Platta filer med numeriska data (MNIST)
- Platta filer med numeriska data och strängar (titanic.csv)

Nu kör vi en övning!

Introduktion till dataimport i Python