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1. Assign a string to a variable is the same as other language by using "=".2. Use $ sign to access a variable. echo $FOOD 3. Use export to create a e 阅读全文
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1. pwd shows the current folder you are working on. 2. Type cd / to go to the root dictionary. 3. Absolute route (cd /home/dq) vs. relative path (cd h 阅读全文
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1. Histogram vs. Bar chart With bar charts, each column represents a group defined by a categorical variable; and with histograms, each column represe 阅读全文
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1. Read the data: 1.1 If the data is not in .csv file. We have to search for the special read method all_survey = pandas.read_csv("schools/survey_all. 阅读全文
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1. Find correlations for each type of data by using corr() correlations = combined.corr(method = "pearson") print(correlations["sat_score"]) note: The 阅读全文
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1. When we match a set of data with duplicated values in a column, and we want to use this column as an unify column which is sharing for each databas 阅读全文
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1. The way to create a DataFrame with its own index and certain columns. state_pop = pd.read_csv("state_population.csv") counts = police_killings["sta 阅读全文
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recent_grads["ShareMen"] = recent_grads["Men"]/recent_grads["Total"] # Create a new column named "ShareMen" , the value is column 'Men' dedide "Total" 阅读全文
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1. If we create a DataFrame, each of the column inside of it is already a set of Series. Does not necessary to change them into a one-column Dataframe 阅读全文
