How can I combine variables with specific partial names from multiple csv files into a single data frame

Question

I am trying to do some analysis of teaching evaluations from multiple sessions with different teachers. Each student's evaluation is stores as a .csv file (although they are tab separated).

My usual approach of combining the csv files into a single data frame wont work because each file has a different number of columns and have the teacher's name in the column name. So there is a mismatch between names and dimensions. I skipped the first line and set header to FALSE, but the different number of columns still throws an error.

So, I read each .csv file into it's own data frame with the same name as the file with:

for(i in file_names){
        assign(i, read.csv(i, sep="\t", fileEncoding = "utf-16"))
}

Is there a way to use dplyr in a loop to rbind columns with specific text in the name across all data frames (50 data frames for this first round)?

Specifically I want to pull the Created.At variable and variables containing ..."Over.all.rating.for.teacher".

Edit to add sample data:

Data1 <- dput(Data1)
structure(list(Created.At = structure(c(3L, 4L, 5L, 6L, 7L, 8L, 
9L, 1L, 2L, 10L), .Label = c("2016/01/19 10:16:08 PM", "2016/01/19 11:08:58 PM", 
"2016/01/19 3:36:24 PM", "2016/01/19 4:06:32 PM", "2016/01/19 4:08:52 PM", 
"2016/01/19 4:40:26 PM", "2016/01/19 6:38:57 PM", "2016/01/19 8:18:20 PM", 
"2016/01/19 8:58:38 PM", "2016/01/20 8:16:28 PM"), class = "factor"), 
    Please.rate.teacher..John.Doe...Skills.of.interaction.and.rapport.with.learners = c(4L, 
    5L, 4L, NA, 4L, 5L, 5L, 4L, 4L, 3L), Please.rate.teacher..John.Doe...Clearly.communicated.goals.outcomes.for.the.session = c(4L, 
    5L, 4L, NA, 4L, 5L, 4L, 5L, 4L, 4L), Please.rate.teacher..John.Doe...Knowledge.of.subject.was.clearly.demonstrated = c(5L, 
    5L, 4L, NA, 4L, 5L, 5L, 5L, 4L, 3L), Please.rate.teacher..John.Doe...Conveys.the.significance.of.the.information = c(4L, 
    5L, 3L, NA, 4L, 5L, 5L, 4L, 4L, 3L), Please.rate.teacher..John.Doe...Class.preparation.materials....referred.to.or.used = c(NA, 
    NA, 4L, 5L, 4L, 5L, 5L, NA, 4L, 2L), Please.rate.teacher..John.Doe...Teaching.methods.facilitated.achievement.of.goals.for.session = c(4L, 
    5L, 4L, NA, 4L, 5L, 5L, 5L, 5L, 3L), Please.rate.teacher..John.Doe...Uses.time.effectively = c(5L, 
    5L, 4L, NA, 4L, 4L, 4L, 5L, 3L, 3L), Please.rate.teacher..John.Doe...Compared.to.other.teachers..this.one.is... = c(4L, 
    5L, 4L, NA, 4L, 5L, 5L, 4L, 4L, 4L), Please.rate.teacher..John.Doe...Over.all.rating.for.teacher = c(4L, 
    5L, 4L, 5L, 4L, 5L, 5L, 4L, 4L, 4L), Please.rate.teacher..Jane.Doe....Skills.of.interaction.and.rapport.with.learners = c(4L, 
    4L, 4L, 5L, 4L, 5L, 5L, 4L, 5L, 3L), Please.rate.teacher..Jane.Doe...Clearly.communicated.goals.outcomes.for.the.session = c(4L, 
    5L, 4L, 4L, 4L, 5L, 5L, 5L, 5L, 3L), Please.rate.teacher..Jane.Doe....Knowledge.of.subject.was.clearly.demonstrated = c(4L, 
    4L, 3L, 4L, 4L, 5L, 5L, 4L, 5L, 4L), Please.rate.teacher..Jane.Doe....Conveys.the.significance.of.the.information = c(4L, 
    4L, 4L, 4L, 4L, 5L, 5L, 4L, 5L, 3L), Please.rate.teacher..Jane.Doe....Class.preparation.materials....referred.to.or.used = c(NA, 
    NA, 4L, NA, 4L, 5L, 5L, NA, 5L, 2L), Please.rate.teacher..Jane.Doe....Teaching.methods.facilitated.achievement.of.goals.for.session = c(4L, 
    5L, 4L, 5L, 4L, 5L, 4L, 5L, 5L, 3L), Please.rate.teacher..Jane.Doe....Uses.time.effectively = c(4L, 
    5L, 4L, 5L, 4L, 5L, 5L, 5L, 5L, 3L), Please.rate.teacher..Jane.Doe...Compared.to.other.teachers..this.one.is... = c(4L, 
    4L, 4L, 4L, 4L, 5L, 4L, 4L, 4L, 3L), Please.rate.teacher..Jane.Doe....Over.all.rating.for.teacher = c(4L, 
    4L, 4L, 4L, 4L, 5L, 5L, 4L, 4L, 3L), Please.rate.teacher..Sue.Smith....Skills.of.interaction.and.rapport.with.learners = c(4L, 
    4L, 4L, 5L, 4L, 4L, 5L, 4L, 4L, 2L), Please.rate.teacher..Sue.Smith....Clearly.communicated.goals.outcomes.for.the.session = c(4L, 
    4L, 4L, 5L, 4L, 5L, 5L, 5L, 4L, 2L), Please.rate.teacher..Sue.Smith....Knowledge.of.subject.was.clearly.demonstrated = c(4L, 
    3L, 4L, 5L, 4L, NA, 5L, 4L, 4L, 2L), Please.rate.teacher..Sue.Smith....Conveys.the.significance.of.the.information = c(3L, 
    4L, 4L, 4L, 4L, NA, 5L, 4L, 3L, 2L), Please.rate.teacher..Sue.Smith....Class.preparation.materials....referred.to.or.used = c(NA, 
    NA, 4L, 4L, 4L, NA, 5L, NA, 4L, 2L), Please.rate.teacher..Sue.Smith....Teaching.methods.facilitated.achievement.of.goals.for.session = c(4L, 
    4L, 4L, 5L, 4L, NA, 5L, 4L, 5L, 2L), Please.rate.teacher..Sue.Smith....Uses.time.effectively = c(3L, 
    4L, 4L, 5L, 4L, NA, 5L, 5L, 4L, 2L), Please.rate.teacher..Sue.Smith....Compared.to.other.teachers..this.one.is... = c(4L, 
    3L, 4L, 5L, 4L, 4L, 5L, 4L, 4L, 3L), Please.rate.teacher..Sue.Smith....Over.all.rating.for.teacher = c(NA, 
    3L, 4L, 5L, 4L, 5L, 5L, 4L, 4L, 2L), Please.rate.the.following.....I.feel.that.I.achieved.the.learning.objectives.for.today.s.sessions = c(4L, 
    5L, 4L, 5L, 4L, 5L, 5L, 5L, 5L, 4L), Please.rate.the.following.....The.session.promoted.ideas.for.dissemination.of.concepts.in.my.home.department.or.other.areas = c(3L, 
    5L, 4L, 5L, 5L, 5L, 5L, 5L, 5L, 4L), Please.rate.the.following.....I.feel.prepared.to.disseminate.these.ideas.concepts.in.my.home.department = c(3L, 
    4L, 4L, 5L, 3L, 5L, 3L, 4L, 4L, 2L), Please.rate.the.following.....I.can.see.myself.making.use.of.handouts.and.follow.up.material.references.that.were.provided.in.class.today = c(NA, 
    4L, 4L, 4L, 3L, 5L, 3L, NA, 5L, 2L), Overall.I.found.this.session.to.be... = c(4L, 
    5L, 4L, 5L, 4L, 5L, 5L, 5L, 5L, 3L)), .Names = c("Created.At", 
"Please.rate.teacher..John.Doe...Skills.of.interaction.and.rapport.with.learners", 
"Please.rate.teacher..John.Doe...Clearly.communicated.goals.outcomes.for.the.session", 
"Please.rate.teacher..John.Doe...Knowledge.of.subject.was.clearly.demonstrated", 
"Please.rate.teacher..John.Doe...Conveys.the.significance.of.the.information", 
"Please.rate.teacher..John.Doe...Class.preparation.materials....referred.to.or.used", 
"Please.rate.teacher..John.Doe...Teaching.methods.facilitated.achievement.of.goals.for.session", 
"Please.rate.teacher..John.Doe...Uses.time.effectively", "Please.rate.teacher..John.Doe...Compared.to.other.teachers..this.one.is...", 
"Please.rate.teacher..John.Doe...Over.all.rating.for.teacher", 
"Please.rate.teacher..Jane.Doe....Skills.of.interaction.and.rapport.with.learners", 
"Please.rate.teacher..Jane.Doe...Clearly.communicated.goals.outcomes.for.the.session", 
"Please.rate.teacher..Jane.Doe....Knowledge.of.subject.was.clearly.demonstrated", 
"Please.rate.teacher..Jane.Doe....Conveys.the.significance.of.the.information", 
"Please.rate.teacher..Jane.Doe....Class.preparation.materials....referred.to.or.used", 
"Please.rate.teacher..Jane.Doe....Teaching.methods.facilitated.achievement.of.goals.for.session", 
"Please.rate.teacher..Jane.Doe....Uses.time.effectively", "Please.rate.teacher..Jane.Doe...Compared.to.other.teachers..this.one.is...", 
"Please.rate.teacher..Jane.Doe....Over.all.rating.for.teacher", 
"Please.rate.teacher..Sue.Smith....Skills.of.interaction.and.rapport.with.learners", 
"Please.rate.teacher..Sue.Smith....Clearly.communicated.goals.outcomes.for.the.session", 
"Please.rate.teacher..Sue.Smith....Knowledge.of.subject.was.clearly.demonstrated", 
"Please.rate.teacher..Sue.Smith....Conveys.the.significance.of.the.information", 
"Please.rate.teacher..Sue.Smith....Class.preparation.materials....referred.to.or.used", 
"Please.rate.teacher..Sue.Smith....Teaching.methods.facilitated.achievement.of.goals.for.session", 
"Please.rate.teacher..Sue.Smith....Uses.time.effectively", "Please.rate.teacher..Sue.Smith....Compared.to.other.teachers..this.one.is...", 
"Please.rate.teacher..Sue.Smith....Over.all.rating.for.teacher", 
"Please.rate.the.following.....I.feel.that.I.achieved.the.learning.objectives.for.today.s.sessions", 
"Please.rate.the.following.....The.session.promoted.ideas.for.dissemination.of.concepts.in.my.home.department.or.other.areas", 
"Please.rate.the.following.....I.feel.prepared.to.disseminate.these.ideas.concepts.in.my.home.department", 
"Please.rate.the.following.....I.can.see.myself.making.use.of.handouts.and.follow.up.material.references.that.were.provided.in.class.today", 
"Overall.I.found.this.session.to.be..."), class = "data.frame", row.names = c(NA, 
-10L))

Data2 <- dput(Data2)
structure(list(Created.At = structure(c(1L, 2L, 2L, 3L, 4L, 5L, 
6L, 7L, 8L, 9L, 10L, 11L, 12L, 13L, 14L, 15L, 16L), .Label = c("2016/09/13 4:28:24 PM", 
"2016/09/13 4:29:11 PM", "2016/09/13 4:29:23 PM", "2016/09/13 4:29:29 PM", 
"2016/09/13 4:29:34 PM", "2016/09/13 4:29:37 PM", "2016/09/13 4:29:40 PM", 
"2016/09/13 4:29:41 PM", "2016/09/13 4:29:49 PM", "2016/09/13 4:30:19 PM", 
"2016/09/13 4:32:42 PM", "2016/09/13 4:35:50 PM", "2016/09/13 4:41:46 PM", 
"2016/09/13 9:41:27 PM", "2016/09/26 10:53:28 PM", "2016/10/11 10:30:34 PM"
), class = "factor"), Please.rate.teacher..Foo.Bar...Skills.of.interaction.and.rapport.with.learners = c(5L, 
5L, 4L, 4L, 4L, 5L, 5L, 4L, 5L, 5L, 5L, 5L, 5L, 4L, 5L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Clearly.communicated.goals.outcomes.for.the.session = c(5L, 
5L, 4L, 4L, 4L, 5L, 5L, 4L, 5L, 5L, 4L, 4L, 5L, 4L, 4L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Knowledge.of.subject.was.clearly.demonstrated = c(5L, 
3L, 4L, 4L, 5L, 5L, 4L, 3L, 4L, 5L, 4L, 4L, 4L, 5L, 4L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Conveys.the.significance.of.the.information = c(5L, 
5L, 4L, 4L, 4L, 5L, 5L, 3L, 4L, 5L, 4L, 4L, 5L, 4L, 4L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Class.preparation.materials....referred.to.or.used = c(5L, 
4L, 4L, 4L, 4L, 4L, 5L, 5L, 4L, 5L, 5L, 4L, 5L, 4L, 5L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Teaching.methods.facilitated.achievement.of.goals.for.session = c(5L, 
5L, 5L, 4L, 4L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 4L, 5L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Uses.time.effectively = c(5L, 
5L, 4L, 4L, 5L, 5L, 5L, 5L, 4L, 5L, 5L, 5L, 4L, 5L, 5L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Compared.to.other.teachers..this.one.is... = c(5L, 
5L, 4L, 4L, 4L, 5L, 5L, 4L, 4L, 5L, 4L, 4L, 5L, 4L, 4L, 5L, 5L
), Please.rate.teacher..Foo.Bar...Over.all.rating.for.teacher = c(5L, 
4L, 4L, 4L, 4L, 5L, 5L, 4L, 5L, 5L, 5L, 4L, 5L, 5L, 5L, 5L, 5L
), Please.rate.the.following.....I.feel.that.I.achieved.the.learning.objectives.for.today.s.sessions = c(4L, 
4L, NA, 4L, 5L, 5L, 4L, 4L, 5L, 5L, 5L, 4L, 4L, 5L, 5L, 4L, 4L
), Please.rate.the.following.....The.session.promoted.ideas.for.dissemination.of.concepts.in.my.home.department.or.other.areas = c(5L, 
4L, NA, NA, 4L, 5L, 4L, 4L, 5L, 4L, 5L, 4L, 4L, 4L, 5L, 5L, 5L
), Please.rate.the.following.....I.feel.prepared.to.disseminate.these.ideas.concepts.in.my.home.department = c(4L, 
3L, NA, 4L, 4L, 5L, 4L, 3L, 4L, 4L, 5L, 4L, 3L, 4L, 5L, 4L, 4L
), Please.rate.the.following.....I.can.see.myself.making.use.of.handouts.and.follow.up.material.references.that.were.provided.in.class.today = c(5L, 
4L, NA, NA, 4L, 5L, 5L, 5L, 5L, 5L, 5L, 4L, 4L, 5L, 5L, 5L, 5L
), Overall.I.found.this.session.to.be... = c(5L, 4L, 4L, 3L, 
4L, 5L, 4L, 4L, 4L, 4L, 5L, 4L, 4L, 5L, 5L, 5L, 5L)), .Names = c("Created.At", 
"Please.rate.teacher..Foo.Bar...Skills.of.interaction.and.rapport.with.learners", 
"Please.rate.teacher..Foo.Bar...Clearly.communicated.goals.outcomes.for.the.session", 
"Please.rate.teacher..Foo.Bar...Knowledge.of.subject.was.clearly.demonstrated", 
"Please.rate.teacher..Foo.Bar...Conveys.the.significance.of.the.information", 
"Please.rate.teacher..Foo.Bar...Class.preparation.materials....referred.to.or.used", 
"Please.rate.teacher..Foo.Bar...Teaching.methods.facilitated.achievement.of.goals.for.session", 
"Please.rate.teacher..Foo.Bar...Uses.time.effectively", "Please.rate.teacher..Foo.Bar...Compared.to.other.teachers..this.one.is...", 
"Please.rate.teacher..Foo.Bar...Over.all.rating.for.teacher", 
"Please.rate.the.following.....I.feel.that.I.achieved.the.learning.objectives.for.today.s.sessions", 
"Please.rate.the.following.....The.session.promoted.ideas.for.dissemination.of.concepts.in.my.home.department.or.other.areas", 
"Please.rate.the.following.....I.feel.prepared.to.disseminate.these.ideas.concepts.in.my.home.department", 
"Please.rate.the.following.....I.can.see.myself.making.use.of.handouts.and.follow.up.material.references.that.were.provided.in.class.today", 
"Overall.I.found.this.session.to.be..."), class = "data.frame", row.names = c(NA, 
-17L))

Data1 has 3 teachers in the session, Data2 has only a single teacher. I think to make sense of the data, and match with other demographic info, I'll need to create a variable for "teacher name".

Edit to show desired output:

               Created.At Rating                                                           Var
1   2016/01/19 3:36:24 PM      4   Please rate teacher: John Doe | Over all rating for teacher
2   2016/01/19 4:06:32 PM      5   Please rate teacher: John Doe | Over all rating for teacher
3   2016/01/19 4:08:52 PM      4   Please rate teacher: John Doe | Over all rating for teacher
4   2016/01/19 4:40:26 PM      5   Please rate teacher: John Doe | Over all rating for teacher
5   2016/01/19 6:38:57 PM      4   Please rate teacher: John Doe | Over all rating for teacher
6   2016/01/19 8:18:20 PM      5   Please rate teacher: John Doe | Over all rating for teacher
7   2016/01/19 8:58:38 PM      5   Please rate teacher: John Doe | Over all rating for teacher
8  2016/01/19 10:16:08 PM      4   Please rate teacher: John Doe | Over all rating for teacher
9  2016/01/19 11:08:58 PM      4   Please rate teacher: John Doe | Over all rating for teacher
10  2016/01/20 8:16:28 PM      4   Please rate teacher: John Doe | Over all rating for teacher
11  2016/01/19 3:36:24 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
12  2016/01/19 4:06:32 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
13  2016/01/19 4:08:52 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
14  2016/01/19 4:40:26 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
15  2016/01/19 6:38:57 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
16  2016/01/19 8:18:20 PM      5  Please rate teacher: Jane Doe  | Over all rating for teacher
17  2016/01/19 8:58:38 PM      5  Please rate teacher: Jane Doe  | Over all rating for teacher
18 2016/01/19 10:16:08 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
19 2016/01/19 11:08:58 PM      4  Please rate teacher: Jane Doe  | Over all rating for teacher
20  2016/01/20 8:16:28 PM      3  Please rate teacher: Jane Doe  | Over all rating for teacher
21  2016/01/19 3:36:24 PM     NA Please rate teacher: Sue Smith  | Over all rating for teacher
22  2016/01/19 4:06:32 PM      3 Please rate teacher: Sue Smith  | Over all rating for teacher
23  2016/01/19 4:08:52 PM      4 Please rate teacher: Sue Smith  | Over all rating for teacher
24  2016/01/19 4:40:26 PM      5 Please rate teacher: Sue Smith  | Over all rating for teacher
25  2016/01/19 6:38:57 PM      4 Please rate teacher: Sue Smith  | Over all rating for teacher
26  2016/01/19 8:18:20 PM      5 Please rate teacher: Sue Smith  | Over all rating for teacher
27  2016/01/19 8:58:38 PM      5 Please rate teacher: Sue Smith  | Over all rating for teacher
28 2016/01/19 10:16:08 PM      4 Please rate teacher: Sue Smith  | Over all rating for teacher
29 2016/01/19 11:08:58 PM      4 Please rate teacher: Sue Smith  | Over all rating for teacher
30  2016/01/20 8:16:28 PM      2 Please rate teacher: Sue Smith  | Over all rating for teacher
31  2016/09/13 4:28:24 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
32  2016/09/13 4:29:11 PM      4    Please rate teacher: Foo Bar | Over all rating for teacher
33  2016/09/13 4:29:11 PM      4    Please rate teacher: Foo Bar | Over all rating for teacher
34  2016/09/13 4:29:23 PM      4    Please rate teacher: Foo Bar | Over all rating for teacher
35  2016/09/13 4:29:29 PM      4    Please rate teacher: Foo Bar | Over all rating for teacher
36  2016/09/13 4:29:34 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
37  2016/09/13 4:29:37 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
38  2016/09/13 4:29:40 PM      4    Please rate teacher: Foo Bar | Over all rating for teacher
39  2016/09/13 4:29:41 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
40  2016/09/13 4:29:49 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
41  2016/09/13 4:30:19 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
42  2016/09/13 4:32:42 PM      4    Please rate teacher: Foo Bar | Over all rating for teacher
43  2016/09/13 4:35:50 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
44  2016/09/13 4:41:46 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
45  2016/09/13 9:41:27 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
46 2016/09/26 10:53:28 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher
47 2016/10/11 10:30:34 PM      5    Please rate teacher: Foo Bar | Over all rating for teacher

Ideal would be something like:

               Created.At Overall.Rating   Teacher
1   2016/01/19 3:36:24 PM              4  John Doe
2   2016/01/19 4:06:32 PM              5  John Doe
3   2016/01/19 4:08:52 PM              4  John Doe
4   2016/01/19 4:40:26 PM              5  John Doe
5   2016/01/19 6:38:57 PM              4  John Doe
6   2016/01/19 8:18:20 PM              5  John Doe
7   2016/01/19 8:58:38 PM              5  John Doe
8  2016/01/19 10:16:08 PM              4  John Doe
9  2016/01/19 11:08:58 PM              4  John Doe
10  2016/01/20 8:16:28 PM              4  John Doe
11  2016/01/19 3:36:24 PM              4  Jane Doe
12  2016/01/19 4:06:32 PM              4  Jane Doe
13  2016/01/19 4:08:52 PM              4  Jane Doe
14  2016/01/19 4:40:26 PM              4  Jane Doe
15  2016/01/19 6:38:57 PM              4  Jane Doe
16  2016/01/19 8:18:20 PM              5  Jane Doe
17  2016/01/19 8:58:38 PM              5  Jane Doe
18 2016/01/19 10:16:08 PM              4  Jane Doe
19 2016/01/19 11:08:58 PM              4  Jane Doe
20  2016/01/20 8:16:28 PM              3  Jane Doe
21  2016/01/19 3:36:24 PM             NA Sue Smith
22  2016/01/19 4:06:32 PM              3 Sue Smith
23  2016/01/19 4:08:52 PM              4 Sue Smith
24  2016/01/19 4:40:26 PM              5 Sue Smith
25  2016/01/19 6:38:57 PM              4 Sue Smith
26  2016/01/19 8:18:20 PM              5 Sue Smith
27  2016/01/19 8:58:38 PM              5 Sue Smith
28 2016/01/19 10:16:08 PM              4 Sue Smith
29 2016/01/19 11:08:58 PM              4 Sue Smith
30  2016/01/20 8:16:28 PM              2 Sue Smith
31  2016/09/13 4:28:24 PM              5   Foo Bar
32  2016/09/13 4:29:11 PM              4   Foo Bar
33  2016/09/13 4:29:11 PM              4   Foo Bar
34  2016/09/13 4:29:23 PM              4   Foo Bar
35  2016/09/13 4:29:29 PM              4   Foo Bar
36  2016/09/13 4:29:34 PM              5   Foo Bar
37  2016/09/13 4:29:37 PM              5   Foo Bar
38  2016/09/13 4:29:40 PM              4   Foo Bar
39  2016/09/13 4:29:41 PM              5   Foo Bar
40  2016/09/13 4:29:49 PM              5   Foo Bar
41  2016/09/13 4:30:19 PM              5   Foo Bar
42  2016/09/13 4:32:42 PM              4   Foo Bar
43  2016/09/13 4:35:50 PM              5   Foo Bar
44  2016/09/13 4:41:46 PM              5   Foo Bar
45  2016/09/13 9:41:27 PM              5   Foo Bar
46 2016/09/26 10:53:28 PM              5   Foo Bar
47 2016/10/11 10:30:34 PM              5   Foo Bar

Please have a look at https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example. It would be easier if reproducible example is provided wtih question. — MKR, Mar 14 '18 at 21:58

JLC · Answer 1 · 2018-03-15T14:00:55.080

Based on some of the other answers and some digging and hacking I tried the following and it seems to work:

library(tidyr)

# Read in file path to .csv subject files
Filepath <- dirname(file.choose()) # Choose a file in the directory
                                   #  with all the .csv files

# Get a list of all files in the directory
file_names <- dir(Filepath, full.names = TRUE) 

# Function to read .csv files listed from directory
read_data <- function(file_names) {
        read.csv(file_names, sep = "\t", fileEncoding = "utf-16",
             check.names = FALSE, stringsAsFactors = FALSE) 
}

# Create a list of data frames from .csv files
data_list <- lapply(file_names, read_data)

# Create a wide data from of all rows from variables
Data_Wide <- lapply(data_list, select, `Created At`,
                    contains("Over all rating for teacher")) %>% 
             bind_rows()

# Gather to long data
All_Data <- gather(Data_Wide, Teacher, Overall_Rating, -`Created At`,na.rm = T) %>%
    mutate(Teacher = gsub("Please rate teacher: |
     [|] Over all rating for teacher|
       [(]Scholarship[)]|[(]Teaching Excellence[)]", "", Teacher ),
       Teacher = trimws(Teacher), Teacher = tolower(Teacher), 
       Teacher = tools::toTitleCase(Teacher))

If anyone has any more efficient or cleaner approaches, please post :)

You have arrived at a good solution. Couple of comments: 1) You can choose directory directly as `Filepath <- choose.dir()`; 2) Argument `full.names = TRUE` can be added to `dir` to remove dependency from working directory. 3) `lapply` could have been called as: `lapply(lst, select, "Created.At", contains("Over.all.rating.for.teacher") )` 4) You can combine all `mutate` in one. Good work. — MKR, Mar 15 '18 at 07:42
Thanks for the suggestions! The use of `Filepath <- dirname(file.choose())` is a workaround because I'm on linux; `choose.dir()` is a Windows-only function (unfortunately). Your other suggestions clean things up nicely :) Thanks!! — JLC, Mar 15 '18 at 13:45

score 0 · Answer 2 · answered Mar 14 '18 at 21:58

0

You could try storing them in a list, rather than assigning each frame into a global variable.

library(dplyr)
read_data <- function(files) {
  read.csv(files) %>% 
    dplyr::mutate(id_col = files)
}
filenames <- list.files(pattern = ".csv")

mydata <- lapply(files, read_data)

That gets you a list with all the dataframes. Then select the columns you want

new_data <- lapply(mydata, function(x){
  dplyr::select(x, Created.At, id_col, 
contains("Over.all.rating.for.teacher"))
  return(x)
})

Note that I cant test this exactly due to the lack of a reproducible example, but this should set you on the right track

answered Mar 14 '18 at 21:58

Conor Neilson

1,026
1
11
27

Thanks! I have added some example data to the original question – JLC Mar 14 '18 at 22:16
Unfortunately, mydata and new_data are both lists that contain all of the variables. The number of variables actually increases to 55 from 36 or 45 (depending on the number of teachers) – JLC Mar 14 '18 at 22:50

score 0 · Answer 3 · answered Mar 14 '18 at 22:13

Here's a shorter way to do it. You can get list of dataframes in your current environment using ls().

In the example below, I select column name from two data frames. This is similar to the problem you are solving I guess:

library(purrr)

# sample dataframes
df1 <- data.frame(name = c('a','b','c'), val1 = c(1,2,3))
df2 <- data.frame(name = c('d','e','f'), val2 = c(1,2,3),val3 = c(7,8,9))


# create a list of dataframes
list_of_dataframes <- list(df1, df2)

# select columns and create final dataframe
output <- do.call(rbind, map(list_of_dataframes,`[` ,'name')) # instead of 'name' here you can specify a vector c('Created.at','another_column','another_column')

print(output)

  name
1    a
2    b
3    c
4    d
5    e
6    f

score 0 · Answer 4 · answered Mar 14 '18 at 22:37

One option could be to use dplyr::select_at and dplyr::bind_rows. The select_at will be used to get only columns containing Over.all.rating.for.teacher or Created.At

library(dplyr)


res <- Data1 %>% 
select_at(vars(c("Created.At"),grep("Over.all.rating.for.teacher", 
names(Data1), value = TRUE))) %>%
  bind_rows(Data2 %>% 
      select_at(vars(c("Created.At"),grep("Over.all.rating.for.teacher", 
      names(Data2), value = TRUE))))


str(res)
'data.frame':   27 obs. of  5 variables:
 $ Created.At                                                   : chr  "2016/01/19 3:36:24 PM" "2016/01/19 4:06:32 PM" "2016/01/19 4:08:52 PM" "2016/01/19 4:40:26 PM" ...
 $ Please.rate.teacher..John.Doe...Over.all.rating.for.teacher  : int  4 5 4 5 4 5 5 4 4 4 ...
 $ Please.rate.teacher..Jane.Doe....Over.all.rating.for.teacher : int  4 4 4 4 4 5 5 4 4 3 ...
 $ Please.rate.teacher..Sue.Smith....Over.all.rating.for.teacher: int  NA 3 4 5 4 5 5 4 4 2 ...
 $ Please.rate.teacher..Foo.Bar...Over.all.rating.for.teacher   : int  NA NA NA NA NA NA NA NA NA NA ...

Note: The data shared by OP contains strings as Factor hence above solution may give warning. It would be better to convert columns to character before operating on data frames.

Is there a way to script this to loop over all ~50 data frames/files without having to name them individually? — JLC, Mar 14 '18 at 23:14
@JLC Yes. That is possible as well. Hint: You can create a list containing data.frames and then run `select_at` one by one and rbind. I can work-out on such answer tomorrow. — MKR, Mar 14 '18 at 23:17
Thanks for the hint. So far, I've been able to create a list of all the data frames in the workspace with `df_list <- lapply(ls(), function(x) if (class(get(x)) == "data.frame") get(x))` But I can't quite figure out how to step through each element with `select_at` and `rbind` — JLC, Mar 15 '18 at 01:42
@JLC Happy to see you have arrived at a good solution. Well done. — MKR, Mar 15 '18 at 07:37

How can I combine variables with specific partial names from multiple csv files into a single data frame

4 Answers4